Okay, I've run into similar issues. On the other hand, I've had players ask if the PvP lamp is lit, and I ask them why their PC would take out a fellow party member. If I feel the reason fits the CHARACTER'S reasoning, I will usually okay it. But then, my group sounds to be somewhat unique in certain regards. Taking the example of the all deadly group(which I've run, and played as one of), these are all professionals at applied violence. They should be getting hired to apply lethal force in a definitive matter. When they aren't hired for a job like that, they should be keeping it to an absolute minimum. One game, this group was "hired"(did it for free) to clean a gang out of a church without killing any of them. They did it for free because the plan got them out of the church, as a matter of fact, the plan wiped out the entire gang, but none of the PCs did anything more lethal than SnS rounds and a Stunball.
I also had that group gank one of their own because they showed a distinct lack of professionalism. An old group of mine would have done it after dealing with the offender's indiscretions one time too many. I've played a klepto in Shadowrun. Most Johnsons wouldn't touch him, and I understood why. A guy that steals a megacorporate server to play video games is not a professional, and you're supposed to be playing professionals, unless you're doing a street level game. At that point, you're talented amateurs. If you're doing a Prime Runners campaign, you are playing the cream of the crop, professionally speaking. Most of your complications are likely going to come from the personal angle, rather than the professional one. One GM was annoyed with me because I recommended watching the Expendables to a new player. I did this because every so often, even Prime Runners will get a wild hare up their ass about something they've seen, and refund the money to do what they think is right.
