This has only happened in one of my games so far, but it's annoying as hell. The entire enemy team rushes for the top of the mall and camps it out with camo. You can't go up a staircase without 2 people decloaking in front of you and sending you back to the respawn screen, it ends up with basically nothing happening as your team can't go up to attack them without being slaughtered and they won't come down.

That and that one douche that is sniping from the window of the big boat on the opposite side of the map.

fail, nothing a grenade launcher/my scar/maximum armor/flashbang/ and a willing team of 6 cant handle. Especially when there are many ways to get into that building. 3 rush 1 side and 3 rush another side.

YOU SIR ARE NOT STRATEGIC! lol

Don't think it's a major issue, even though I always play alone, I usually go up that building in various directions, always getting a flank on some people, if they are camping, you know where they will be. Go prepared.
Grenades can be held for a while in order to explode when they reach the area, this can help to prevent people from running away from it.

Yes, learn to play in a team. They may be camping, but it's the fact that they're camping as a team which makes it successful against a non-coordinated group of players on the opposing team.

For all those saying "play as a team", keep in mind that the game matches teams up with randoms. People don't usually talk, much less strategically attack with you. And if randoms and teams are gonna be matched up together, there shouldn't be such hugely overpowered team tactics.

Thanks to the guy who suggested cooking frags.

Then go play instant action, where there is no team, you have to kill everyone. So I doubt there will be people teaming up and so on.