Yes, a lot. Mostly on Garry's Mod, specifically RP servers, but also on other games. Like a while ago on WoW, the server I played on was fucked in terms of population. There was only 20 lv80 Alliance players on at peak times, so we all decided to make a guild and camp various Horde questing areas. It got a huge response from the Horde players, was quite hilarious. The thing is, I don't even give a shit if someone does it to me. I don't know why, I just don't take games seriously at all.