Much like Anfield suggests below, I just put pressure on the snipers by flanking or just getting close one section of the map at a time. Usually the guys who snipe all the time aren't very cool under pressure when it's happening in their face. Much like my TOO strategy against campers. Don't sit back and play footsy with professional footsy players. Attack and put pressure on them. They don't do well under pressure that's why they camp.