Look for a FPS that doesn't have as many hackers?
A F2P game will have more hackers than a P2P game and typically the hosting company won't address the issue until it's too late. Your best choice is to either get used to it and beg that a hacker doesn't join your room or to look for another game.
Hackers are a pain I give you that, I remember the horrible horrible days when every single freaking map in Maple Story would be screwed because there was a vac hacker keeping all the mobs in a hidden corner of the map. Sometimes it gets solved, but most of the times it doesn't (lol Gunz).

