To be honest I don't care if I see a camper in my lobby.
The person camping is more than likely new to the game (noob) and is then an easy target for me.
I don't find them much of a problem because of the fact you learn to accept it. Every Cod will have them so its about how you deal with them. What I do is use my Engineer class to see their betties and shock charges and a C4 to clear the rooms.