Cheating and Collusion
In your poker career, you will probably find a cheater or collusion at a table. The best response is simply to leave the table. Many people are afraid of collusion or cheating at online sites. It certainly exists, but not any more than it does at regular casinos. In both cases your best defense is to identify it and leave the table. Some times if you identify colluders you can take advantage of their tactics and make a lot of money from them, but that's a risky play.
I encourage you to put any thought of cheating or colluding from your mind. It's simply not worth it, it doesn't give you a very big advantage. If you spend your energy improving your poker play, it will pay off much better than trying to find ways to get an unfair advantage.
[@@ types of moves that colluders or cheaters do]