Unlike in Quake, camping is a valid tactic in this game. There are times when you wait until an enemy gives away his location or walks by and you follow and take him out from behind. This is just good playing. But I have seen a player wait behind shrubbery ('nee!') until an enemy walks by, jump out and shoot, only to be killed by the enemy that was following. In such situations, smarter players will 'camp' until they know the locations of the enemy. Then come out and take advantage of their newly gained military intelligence by attacking from a position of advantage, perhaps when the leader has gone past a wall where he can't help the guy in the back. This game sometimes requires patience to play really well. Also, observers need patience to wait until the game finishes to respawn. If you don't have the patience, there's always Quake or Unreal
