If 2/3 platers get together on a 6 person cash table they can make plenty of money working together. Especially with bloody msn messenger group chats

Basically what theyll be doing is letting whoevers been dealt the best hand play each time, or all going in and splitting the winnings once they leave the table. Theyd still lose some but between them theyd be making themselves 2 or 3 times more likely to win money from the other players, theres probably loads of obvious raising/calling methods for them too.
Easiest way to look at it is from the perspective of the victim, if youre seeing a flop with 3 people in collusion then obviously youve got one chance to make a hand of it and they have 3.
Apparently theres loads of security software now that can tell when players are constantly folding AK to AA pre flop or whatever, youd both be banned instantly and blacklisted elsewhere.. it aint worth it, especially as the high cash tables will be the most monitored.