Chainsaws and monowhips cause really, really messy fight scenes. These are the kind of scenes that tabloids and even legit news sources love to get pictures of. These are the kinds of scenes that make runners look like serial killers. These are the kinds of scenes that give a street sam the same kind of heat as a mage dropping mind control or permanent transmutation magic on people.
Sure, if the Corp wants to bring news media into their super secret and totally illegal base for them to take pictures. I mean it is terrible PR for the corp and will tank their stock prices, but it could be a thing. (Especially as a "sabotage someone else in the corp" revenge / promotion seeking type thing.)
Oh, how wonderfully untainted you are.
- Corporations own the news media. They don't have to say where you attacked, or what the location was for; a 'think tank' can be anything, and pass around the nachos, you're on the 9 o'clock.
- If they want people especially horrified at what you've done, all they have to do is shift the location of your attack to a 'think tank' location in the middle of town which they can claim is secure, but that it's low security and they'll share what information they have because of such an egregious crime.
- If it's especially nasty, they'll recreate the scene - or even move the entire thing - to a location they CAN let 'independent news media' into. They might (though probably not) even let external law enforcement in to take a look. They'd at the very least share the information.
So using a weapon like these is absolutely ... well, however you want to look at it. Pink mohawk, stylistic, making a statement, getting messy, whatever. It'll make people pay attention, that's for sure. And like Beta says, it's sure to give you a rep.
If they are willing to go that far what's to stop them from faking scenes when you don't leave a body count behind?
What Shadowrunners are willing to work for a corp that burns Shadowrunners on the news media? Shadowrunners aren't the only ones with a rep to worry about.
Shadowrunners exist. For that to be true, corps can't burn every Shadowrunner who hits them on the 9 O'Clock news.
ALL the corps burn Shadowrunners in the news media. Sure, they usually call them 'terrorists', but burns are burns. And the way you don't get burned in the media is by not leaving a facility looking like a Jackson Pollack painting done in blood. This is where the SHADOW part comes in. As in, not making a big, flashy scene that the Corp HAS to respond to. You go in with an AK-97 and tactical gear (including masks), make clean kills, and limit collateral damage, and you're not going to find yourself on the news, unless whatever you hit was already in the public eye. You go in with chainsaws and monowhips, leaving bodies in pieces, and that's going to make people want to come find you. That's the kind of thing that brings heat on you, and the corp can spin anything bad at the facility as unimportant, because look what those horrible psychotic terrorists did! What makes more of an impact on the general populace, a drone strike taking out twenty people in some middle eastern city you've never heard of, or terrorists cutting one guy's head off on a live stream?
Corps don't burn Runners who stay low key, unless they hit something insanely high profile. Don't care how good you are, you hit a member of a AAA corp's board, you best NEVER let it get linked back to you, even if it was another board member who ordered the hit. ESPECIALLY if it was another board member who ordered the hit. Same with stealing millions of nuyen from a company. You do big things, and they'll come after you, with any and every tool at their disposal, including the media.
Hell, there's even a difference between using a sword and using a chainsaw. Yes, both will kill you dead. But the chainsaw is messier, and leaves a more visceral impression on people than a sword. You see someone's head cut off by a katana, that's nasty, but it isn't completely outside what you expect. You see someone take a chainsaw and go cutting torsos in half long-ways, and that freaks the hell out of people. Frightened people lean really hard towards the 'kill it with fire' button.