While I normally don't complain about campers, I have to bitch about Grifball campers.
In the Reach-based levels, there are often ledges behind each team's spawn points that can be jumped upon easily by the ball carrier. Once he's up there, the enemy has only one way to attack him: In force, while slaughtering his entire team. If you can't do so, they stall up there until the round ends (even during Overtime). Even getting to him is hazardous, but once you do you also have to contend with his ability to melee you. And Tzeentch forbid he drops the bomb in a corner, because you cannot get it without getting Hammerlaunched or a well-timed lunge with the sword. And the worst ones are the ones that do this right off the bat, without even scoring a single point.
The thing is, Grifball is supposed to be a Halo-based virtual sport. How sporting is it to just time out the clock without scoring at all? Spawn-camping at least has opportunities for the players to escape without needing extreme luck. The Ball Campers aren't even playing; they're just sitting there watching other people play for 15 minutes.
Fucking assholes.