Shit gets real in the streets often on Tich; although the majority of people are pretty good about leaving each other alone to quest.
It's like all those racially-motivated movies though; you can feel the tension and every once in a while BOOM! it bubbles over and everyone murders each other. It usually starts with some idiot PKing someone else, and 2-3 other dudes see it happen and then kill that dude, who then get attacked by other guys, and then the entire area just rolls into a skirmish.
A lot of accidental blood baths happen too simply because some idiot on the other faction is standing over the quest giver. You click and you're attacking. At least the NPC guards are moderately retarded and don't instantly gib you.
Nice to be a rogue though; doesn't happen too much to me