I believe camping is the process of erectin a tent w/ portable everyday items in a woodland area, or similar non-urban environment.
I joke, I joke...
It is a fairly cheap tactic. Although I think it depends. If you camp an area then I don't suppose it's too bad. Like say, MW2 underpass, when you run back and forth between where A and B are on domination, because it involves movement, and you have cover and can be sneaky. It's tactical. However, waiting at a door entrance is *****-like and generally means you're too lazy to actually play the game and just want points. I've also noticed it's campers that scream down mic's the most about "bullshit" when someone they've killed 4 times kills them. Also, just for the record, camping at say, flag A. Well that's not camping. I don't want you to steal the flag, so I kill you when you try to. Simple.
[small]Also, a little off topic, but on hardcore mode, the RPD goes through ANYTHING, and I mean ANYTHING. Concrete, steel, aeroplanes, the lot.[/small]