The problem is most MP is filled with people who don't give a crap about strategy - they just want to run around like maniacs and shoot everything they see - so, when that play style (which is the only thing they know) gets them killed by snipers and/or campers, they cry bloody murder because they think EVERYONE should be running around like me!
Personally, I utilize a mix of camping and moving - I move toward where I see skulls, then I hunker down and wait for said morons to come running around the corner and collect the kill and then move on.
Campers are people who pick one out of the way spot and NEVER move during the entire round - I can't see the fun in playing like that. I'd rather be mobile and have a negative k/d ... I've noticed that with nearly 100% consistency, true campers are almost always at the bottom of the score chart by round's end.
Anyway, if you like sniping, great - the point of the game is to have fun, not gain the respect of your peers... listen to them between rounds they sit there with their pre-pubescent voices going "eff you ni**er! ..." thath's the mentality you are dealing with - why would you give a moment's care what their opinion of you is!? If your style gets you a higher score, do it!
Anyway, while I don't play COD unless my cousin brings it over, there have been some funny things between us. There was this one time when I was behind this wall with a gap in it at the bottom, and managed to take him down as he walked by it while looking for me. Another funny incident was when he was hoping I'd trip over his claymore. What I did was throw a grenade and disarmed it.
As for the accusation of camping, it's been a strategy in first person shooters since at least Goldeneye for N64. I mean, you could hide in vents and secret passages and shoot unsuspecting targets that are looking for you in that game.
"Michael Vick was arrested for getting in an assault plane and shooting down other planes?" - L0Z
Not camping if you're sniping or defending an objective.
Only people that get killed constantly by a sniper in the same spot over and over or repeatedly run to open objectives and die call those camping. Camping is more sitting in an obscure corner with a regular gun ADS'ing down an isolated hallway or doorway.