Eh, maybe I jumped a bit in my wording. Pulling off mass murder in a way that the RP justifies it is preeeeeeeeetty difficult. Only instance I've seen of it was with Xander as a malf AI that continuously and blatantly hinted at "cleansing fire" when he was setting his AI out as a God on the station if they didn't obey; and that was repeatedly through announcements and massive amounts of chatter on the radios. When push came to shove, plasma fire simulation.
Then there's situations where nuke ops go "Leave the station or die" and they think "Oh, that's the RP. I have clear reign to KOS because I gave them an option" and that's where they got in trouble.
Here's the most important thing, though: If you're going to plot something like this, then first and foremost you message admins; like you did originally. The way you were asking in the beginning, though, made it seem like "People are atmos griefing. I CAN DO TOO BECAUSE LAWS?! :D" and that's where I had to be like "No. Stop." because it seemed more like you simply wanted to kill people without caring for RP, and that's why I was pretty short on my wording because I simply wanted to get to the point of "No, you can't grief, stahp". Apologies.