certain games require the camping tactic. if your with a bunch of higher levels who rape you every 15 seconds, hiding in a dark place and waiting untill they run past can be effect way of getting kills and points for your team. I wouldn't see the point in camping in games like Conflict though, going to lose the round and only pick up 3/4 kills at a time.
Also think certain levels require a nice comfy seat in the dark pit of the sewer. (under ground is always fun) there are some levels i find it pointless, like archives, only a matter of time before your head crumbles into a thousand peices anyway, why not come up with a tatic, even if it is a simple one like doning a shot gun and running laps, pumping lovely amounts of shrapnel into peoples eye sockets.