Going a bit off topic though. Killing people who are there minding their own business in photo shoots or car meets that pretty much on the level of tank grieving. People bitch about the tank grieving because you stand no chance to begin with just like the car meet/photo shoot people stand no chance when you throw in your murder surprise at them.
I agree that's f*cked up, but the game allows it and it just happens if you do car meets in public sessions. Free roam is a dangerous place. And it would be incredibly stupid to assume that 16 players in a lobby with guns are going to follow the Geneva convention's rules. This is GTA, not a 19th century duel between gentlemen.