[Boomstick]

If the other players assist him, then it is like regular run, just have you to improvise, that is not so bad. Derailling the plot? So what? Runners are heroes, when they are involved. Else, story's going on.  You could have them facing the consequences of not being serious at this game/for a run. Also, I don't think other players would like their PC being nailed just because the other guy goes overboard once too much.

But if that guy is really breaking your game out of personal problems with you (or because of his personality), well, ask him why? Maybe he is bored because he thinks you don't give them real challenges, or because you don't take their background into account.  Or maybe he likes being over the top and wander in the RPG because he would not be able to do it on console or in RL (because RL sometimes railroad you in some matters, granted you want some thing accomplished.).
Or maybe is just an asshole. Then you can also talk to other players after throwing him away, because if they are not really assertive, then they will listen you to convince them playing without him. And if they like him so much, that means they are alike, just less assertive and needing a leader. So you won't lose anything leaving.

[DamienHollow]

Like I said. I've tried. Even the ones who concede that I have a point take the "talk it over" stance. So I tried to talk to him. It never helps. It might get him to lighten up for a day but then he's right back to doing this sort of thing. The others put up with it. I left the group for six months. Spent six months trying to find another group, found plenty of D&D 3.5 groups but I frankly don't like that system. All of the Pathfinder groups would slash large numbers of classes and races even from the Core and Base lists. And nobody else that I can find in this valley plays Shadowrun of any edition.

As for his personality, I'm seriously starting to think he's a Histrionic.

[Reaver]

Ok, I don't usually condone this type of think, but sometimes, it just has to be done....

This is what I call a "F**K over Waldo" run <evil grin>

1)   The run is simple, they are to raid a corporate office and make off with a gizmo (don't care what it is). However, you have something near the run zone that you KNOW the player will grab (with him making off with servers and such, this should be no problem). A high end data store, Commlink, or other info device is best.....
 
2)    They go back to the Johnson and get paid.... no big deal.... till the Johnson turns up dead by a horrific means. (in my game, the Johnson was peeled with a potato peeler, with large amounts of antiseptic and coagulate  used on him... to keep him alive as long as possible) Most runner will go "huh tough break.... lets look over our loot!" This is when they find out that the info device is HIGHLY encrypted and a host to multiple databombs, black IC and other levels of nasty. (Most greedy players see this and see dollar signs! they will spend a lot of free time trying to crack the sucker open... or looking for someone to crack it)
 
3)    At the same time, if any of the players get in touch with a contact, ASK them to make a loyalty roll. If they succeed, the contact tells them some ominous like "Hey, there was a large man in a black suit asking about you" or, "Man is you handle generating a lot of traffic on the matrix right now!" or "Hey, why did you rape/brutalise/murder/torture that <insert vulnerable member of society here>?? you didn't have to do that!!"
   If they fail the loyalty roll, the contact acts panicky, nervous, scared, and is not much help. (loyalty 3+). Or they act like character is their best friend, and his happy to see that and glad they called... and drops several lines about how they should "hook up real soon for beers and what not!"(loyalty 1-2)
  LOYALTY 3+:
   If they check on the contact (physically) they find the poor contact's home has been trashed and the contact is barely holding onto life. Once he has recovered to the point of talking, he tells them that several men showed up asking about the character! How they knew, he knew them, he doesn't say. but they are really insistent that up with the character like RIGHT NOW! The Men in black even took his wife/child/girlfriend/dog/cat/hamster hostage and expect the characters to contact them ASAP (the contact has the number....) If they do call, proceed to #6
   LOYALTY 2-
  The contact will set up a meeting for the get together someplace the characters have never been before.... a Bar, club, or restaurant (or, from the outside looks like a bar/club/restaurant. As the character(s) enter, they soon find the contact, Dead. And men in black armor come in blazing after tossing flash bangs (Ambush rules time!) there should be the same number of men in black as to characters +2.... if more then 4, then one will be a mage. if more then 6, then 1 will be a mage, 1 will be an adept. The goal is to capture the character(s), not kill, so they will be using mostly stun ammo and weapons.
   If they get their hands on the character(s), when they wake up, they are alone in a white room with VERY bright lights shining down from the ceiling, and mounted on the walls. They are strapped to a chair, nude. (if they are a mage, they have been outfitted with mage restraints. If they are a social adept they are gagged). A little man comes into the room pushing a cart loaded with medical instruments, and a few odd items. Notably several large books, and gas powered "hotplate". he begins to speak to the character(s)

5) "Do you have any heart or respitory problems I should be made aware of before we begin? A history of seizures? or allergies? No? good. Allow me to introduce myself, I am Dr. <insert simple name here> and I am here to over see your vivisection. We will be starting off with 200cc adrenaline to keep you from blacking out, so you will remain awake while I ask you a question. We will only stop when you answer the question. Do you understand? Good. First we will start with the removal of the dermis, then the epidermis, followed by soft tissues, tendons, then muscle tissues and fibers, then bone tissue. We will be avoiding organs, nerve tissues and fibers, and process functions of the brain. To do this removal, we will be relying of the 4 elements of interrogation. Hot, Cold, Sharp, and Blunt. Which one would you like to start with?"

The question is always the same "Where is the <insert stolen device>? Who has it? how is it guarded? have you cracked it yet?"
Now, most players can not play fear at all, they will passively sit there while horrible things happen to them, happily spitting in the Doctors eye. THIS is what "composure" tests are for. let them roll. then have the doctor remove some skin. then have them roll again with a modifier.... and the doctor removes some more.... then roll again with a bigger modifier... and so on. Until they fail 3 times and the doctor is satisfied with the answers and is sure they are telling the truth. Even if they answer right off the bat, he still removes several sections of skin/muscle/tissue/bone, (just to make sure)

*****if they are all captured I recommend using notes between you and the players to keep the other players from knowing exactly what happens to the others, and who talks first.***
*IF only 1 runner was captured, its only a question of how much damage is done before cracks (if its not the offending character, Hope that it is not too much!). The men in black then dispatch a drone to the location to recon the area. if it spots the runners that are still on the loose, it drops down to deliver a message: (see #6, but modify it to reflect that it is one of their team they have)

*IF the entire team has been captured and it is simply a matter of picking up the device, the players will remain in custody until the device has been picked up. Once it has been the runners will be drugged and then dropped nude in some part of their neighbourhood close to where the device was picked up. The runners, missing their equipment that they went to the meet with and most likely several patches of skin (or worse!!) should consider themselves lucky the men in black didn't just finish the job and kill them off.

But hey, good shadow talent is hard to find! If the players have a good reputation, then before they got dropped off, they actually underwent some "un" elective surgery... in the way of a Cortex bomb! When they are dropped off, they also have a commlink with them. Once the awaken the Commlink goes off and Doc whats-his-name starts talking: "Good to see that you are awake, Do you have full sensation of or limbs? no tingling? good, I hate opening the skull of a patient, so many things can go wrong. Let me be straight with you. inside your head is a cortex bomb with a 18 month battery supply. Keep this commlink with you, on occasion I will have assignments for you that I expect you to carry out for us. If you refuse, we detonate the bomb. If you try to remove the bomb, we detonate the bomb. If you require headware implantation you will contact me through the link. If you try to have any headware installed without us, we will assume you are attempting to disable the cortex device and detonate the bomb. Am I clear? good. Rest up. You will have a busy future ahead of you. And welcome to <insert Corporation name here> I am sure you will prove yourself to be a valuable member of our team!"

6)  If they call the number provided by the contact, a person picks up after the 2nd ring. and says the following:
"Hello, you can call me Mr. <insert simple name here>. Am I dealing with amateurs? or professionals?"
If they say Professionals:
"good then this will be easy. I have something you want back, and you have something I want back. A simple exchange. Once I confirm that the <insert stolen device> is correct, intact, and uncracked, you can have what we took from your friend. The verification of goods and exchange will take place at <insert address for underground parking lot>, middle level in 3 hours. please do not be late. This number will not work after we hang up, there will be no second chances on this exchange. If you are late, the item in my possession expires. And we start again from square one. Do you understand? Good"
If they say they are amateurs:
"Hmm, then this will be difficult. I know you will not believe I am serious unless I send you so choose. Hand or Foot? Go to this matrix address in 5 minutes, enter in this passcode, view the film, then call me back"

If they go to the matrix address in 5 minutes, there is a freshly loaded and sanitized video file that shows the terrified hostage strapped down to a table. A man approaches with a bone saw, and promptly removes the agreed upon appendage, while the hostage screams and writhes in pain and fear.

If they call the number back repeat basically what is said up top, but modified to reflect the fact that they are amateurs and the man will brook no nonsense from them.


7)  At the parking garage, the area has been blocked off with construction tape. the characters can either drive down, or walk down. On the middle level they spot the hostage tied to a chair in the middle of area. strapped around the waist is a large device with many blinking lights. A small drone hovers nearby, as the players enter the area, the Drone begins to speak.
"your property has an explosive device attached to her. If you attempt to remove it, it will detonate. Under the chair is a commlink, please retrieve the link. One you have placed our property in the drone, we have recovered it and verified that it is uncracked and correct, well will transmit the code to release the bomb."
*IF the players shoot the drone, the bomb goes off, killing the hostage. The men in black will simply start again by grabbing an other contact and going through the procedure again (and be more displeased with the players)
*IF they tampered with the stolen device, or cracked the encryption, or placed a substitute device in the drone, the bomb goes off. The men in black start again with another contact.
*IF they try to hack the drone, they find it is controlled by a rigger who knows his stuff. He gives them a warning to leave. If they don't the bomb goes off. the men in black start again.
*IF they place the device in the drone, it has not be tampered with and is uncracked, the commlink under the chair beeps with a code to enter into a keypad to release the hostage. NOTE: if they have gone through this procedure before, the players decide to co-operate, the bomb goes off!



*****
While there are many ways to mess with and actually track down the men in black, by the time they do so, they should be down several contacts. As well as have their reputations run through the mill simply because their greed started this blood bath. The men in black turn out to be corp special operations from the corp that they stole the device from. Apparently the runners missed some survailance drones/equipment on the original run and it captured they appearances on film as well as their profiles, and anything they said during the run. Using that, and the corp's network of fixers, fences, and contacts they were able to get a partial tracking on the runners. Not enough to know where they are/were but enough to get a line on some/all of their contacts.

IF they managed to crack the encryption what they find is......... nothing of real import! there is some progress reports, some projection reports, and status reports of various divisions with in the Company. If they look really hard, buried in the Emails they find some correspondence between a Manager and his mistress. It would seem that this manager (a basic nobody in the company) has sent the special operations team after the runners to keep his little love affair a secret from his wife! He feared that the runners were going to attempt to blackmail him with the emails and end his marriage (and ruin him financially, since most of his money goes to either the wife/lifestyle or to maintain his mistresses lifestyle, he has no money to pay for the blackmailing! he figured he would tell HR that the device contained "sensitive Corporate secrets" and had to be recovered quickly.... hence the Special Operation team.

[Crunch]

It's inherently a problem if the extra theft isn't disruptive. If it is disruptive there are a few options you can look at.

1) Let the random theft be the maguffin that leads to a campaign mini arc. The runners steal something so hot that the Corps, the Mob, the Yaks and another runner team all come after them looking for the paydata.

2) Have a run time out because of the random looting. They would have gotten away but because of the random looting they barely miss escaping from the QRT.

3) Some of the miscellaneous loot is tagged and lets the corp they hit backtrack them. Maybe it even burns their fence instead of them.

4) Their Johnson is pissed off that they're so unprofessional that they're looting on a run and their street cred takes a hit.

5) Their Johnson is actually working for the corp they hit, maybe the run is against a rival department, and he's so pissed off he tries to burn them.

6) If the players would actually have more fun as smash and grab thieves try running that game instead. Substitute crooked fences and twisted mob bosses for the usual window dressing and go for it.

[ZeConster]

Before you walk away and/or kill the entire party, I recommend one more conversation with the player. If he keeps the money to himself, explain that he's basically taking up party time and making things more complicated for the party solely for his own enrichment.
Of course, regardless of whether he keeps the money or shares it, explain that there are logical consequences to this: aside from numbers 3, 4 and 5 on Crunch's list, there's also the fact that shadowrunners only survive because they don't piss off the corps enough to pursue them at all costs - and guess what? Stealing corporate secrets or backup servers (a prime place for higher-ups to stash some secret data) will get you there quick.
Now this is the most important part: if he doesn't listen to you, even if you quit, make sure his habit actually does get the party killed first. He needs to learn actions have consequences.

[I_V_Saur]

I had a party that was moving in from a long history of DnD, myself. I knew this would be a problem, that even I would encounter the issue if I was playing. My solution was quite effective, I believe.

Here, have this.

And this.

And this.

This too.

Make them suspicious, jumping at shadows, waiting for the other shoe to drop. Have their contacts unclear about half the stuff they're getting.

On a similar note, I have a party that had trouble looking under the basic surface, (vital Runner skill) so I gave them a mission to retrieve some telesma, bring one crate to the Johnson, and dump the rest. The catch? Johnson wanted a crate that turned out to be Dragon Scales.

Railroading is when you don't give them other choices.

Sometimes, a few words in private help a person smarten up, or explain the issue. Sometimes, it takes a close shave with one of Lofwyr's pet runners, and GM confirmation that it cost them more to take the extra than it did to use their head.

Some looting, in any system, is understandable. When players push those boundaries, heap it on until they learn discretion. Don't tell them to stop it altogether - be sure to enforce the idea that some of what they're doing isn't a bad idea. Use overkill to encourage moderation.

[Trickery]

Ok, I don't usually condone this type of think, but sometimes, it just has to be done....

This is what I call a "F**K over Waldo" run <evil grin>

That's a pretty epic scenario, Reaver.

Almost makes me want to act like a complete ass in game on the off chance the GM decides to throw one of these at us. >.>

[All4BigGuns]

If only one person thinks there is a problem and it looks like the others 'are being too passive', then chances are that there actually isn't a real problem and the 'passive' ones are just basically blowing it off.

[ZeConster]

If only one person thinks there is a problem and it looks like the others 'are being too passive', then chances are that there actually isn't a real problem and the 'passive' ones are just basically blowing it off.

Of course, when several of the others admit there's a problem, those chances aren't as high as you think.

[Reaver]

I'm all for taking a time out to discuss an issue with a player concerning his attitude and behavior. But sometimes that doesn't work.

Then you are left with two choices. remove him from the game, or "be an a**hole".

Some player's have it in their heads that as a player they can do anything they like..... regardless of what the rules say. This is usually when I show them that, while they can do a lot as a PC, their actions can, and do have consequences. If this leaves them a crippled pile of goo... so be it.

.... and some people just like to watch the world burn. these I ask to leave. and if they don't, Then I usually do. If leaving is not an option for either of us.... then I employ the "Gonna f**k you over until you smarten up" approach up top. It is amazing how fast some people learn that it is simply easier to "play by the rules" then spend hours remaking characters, only to watch them suffer some gruesome fate 2 or 3 games sessions later.

[Mystalya]

Ahahah....I pretty much always look for more loot when playing an infiltrator/thief. 

Stealing is fun RP-wise. Even if you don't get much out of it you still feel like "Haha, I got their stuff anyway." Even when playing magical characters i will keep an eye out on jobs for magical goods and try to turn them. It honestly just seems like good business to me and what a Shadowrunner would do.

Petty thievery. Honestly, it sounds like this guy just gets off on RP-ing that. Even so, my characters would never put someone on the team in danger or stay against a bomb countdown, jump into a pit of AIDS etc. 

From what else you've described though it sounds like this issue runs much deeper. If he's intentionally running all over you and the group and ruining your games that you put work into then not only does he not respect you as a GM but he doesn't respect YOU or the group as people.

If he is nt listening to out of game discussions then I would advise what Reaver said and use the "Gonna f**k you over until you smarten up" approach.   "Hey! Who put that sniper there?!" 

Another thing that is important. If your group likes you as a GM and want you to continue then they should have the balls to stick up for themselves and you. If they don't then I really honestly believe you're better off without.

[Nobody]

The bane of the D&D style thief? items. Things that screw you over from the moment you decide to touch them . . .

There are plenty of secrets in Shadowrun that you just don't want to know about. Just like reading books in Cthulhu, snooping gets you in trouble. Put those things in his path. If you steal enough nodes from black sites eventually you'll happen across a [captive dissonant sprite/corp loyal AI/awful hypervirus/paydata that'll get you D-E-D fast]. Sticky fingers at the talismonger's warehouse? Hope you like dealing with [the mage who's ritual that can only be performed once per cosmic cycle you're holding up/devious inhabitation spirit trapped in an innocuous object/consignment object from the Yakuza].

Rather than just grumble and funnel his stuff into the black market never to be heard from again, let them be the seeds for stories. Fuck over Waldo (which is perfectly in-genre) is once such seed, and after you've used that, you can find another. Hell, a solid chunk of the time that should probably happen with the legitimate run target 

And if he's keeping it from his team, and it puts them in danger, I've had parties sell out the thief for the bounty.

[Mara]

Shoot...I think I might use the **** over Waldo scenario as part of a normal storyline...My players aren't
QUITE paranoid enough right now.

Also, frankly, I do not see much of an issue with extra stealing on a run, provided it makes sense. It CAN be
the mark of a professional, after all, if they come across something very rare and hard to get normally, and
they take it. This is how my group got their Tiburon and Appaloosa, after all. But, there is the difference between
Professionals and Amateurs. As Pink Mohawk as my game has been, my players stick to their objective, and don't
go off mission.

[Michael Chandra]

Have one more talk with him. Make your issues perfectly clear. Do not tell him there will be consequences. Don't tell him what you'll do if he doesn't listen, even if he asks about it. Either he listens, or he'll find out.

Prepare a backlash. A heavy one. It doesn't matter what. Waldo is too much, but prepare a backlash. Make sure it doesn't depend on what exactly is stolen.

Run another run or two. Then, give them an easy run for a change. A milk run, too easy, or so it seems. If they only steal what they're supposed to, they have a car chase afterwards, have to toss the tail, give the item to the Johnson and they're in the clear. They'll see the Johnson on the news later, killed horribly "in what appears to be a mob-related shooting". But nobody's going after them, since they already delivered the item and who cares then.

Sticky fingers decides to steal things? They're no longer going after the Johnson. They're going after the party. Make sure at least one of them dies before they finally get given a chance to surrender. If they surrender, let them execute the thief, take the stolen goods and leave. Oh, make sure to kneecap the others. If they run away with the goods, they'll be hunted down until the stolen goods are recovered. The enemy will know who to gun for, so someone's going to be the focus of most of the fire. If they're smart enough to leave the goods, then run away without them, make sure they still go on until the thief is dead. After that, let a megaphone laugh tell them "run on now kids, and remember not to fuck with us again".

If he (or anyone else) burns Edge to survive, fine. Just keep in mind that if someone goes down, the enemy will make sure to doubletap if they got the chance. Twice. So the scars will be nasty.

If they're still willing to play after that, go on and do runs. Next time anyone steals the wrong goods, make sure someone comes after them again and they recognize the style. After digging they'll find out that these guys put themselves for hire as recovery team and like sending message.

[GiraffeShaman]

It can be effective to have repurcussions from the excessive looting that fall down on the heads of all the team of runners, not just the looter in question. Quite often they will do your policing for you. You don't need to utterly destroy them either. Just cost them money or reputation and make sure the team knows what caused it. Most players will get tired of it quite fast.

If you're feeling exceptionally cruel, then have an outside party offer the looter an extremely rare/expensive item in exchange for betraying his team and the current Mr. Johnson on this particular run. (Make sure it's not something that will appear to actually get their team killed or they are less likely to bite) Then later on have the betrayal revealed.