I've witnessed obvious collusion playing live at the casino I play at regularly. I've been at a table where two players were removed from the table by the floor manager- literally asked to pick up their chips and come with him-- because they caught them colluding using cel phones at the table.
I think you would have to be fairly naive given todays countless means to communicate with other people, to connect people, to form alliances, groups, whatever- that collusion isn't a part of online play-- in nearly every game and every tournament one could join.
It is just too easy-- it's as simple as that.
I've heard the suggestion "don't play SNGs, or cash games, only MTTs".
But the truth is that while YOU may not have the network of friends or collegues in the poker world who would be able to "work" a MTT as a group- a lot of people do.
Given the amount of money which could be made, I would not be surprised if there are fairly large player groups who play in highly coordinated shifts, communicate over IRC or VOIP, and are able to avoid detection.
Given the relatively small player field of most MTTs online, which is typically under 200 players for most games- a group of 10-20 players (which I do not believe is unrealistic) who play the tournaments together and use both collusion and chip dumping-- even if only say 6-10 are playing at a given time... would end up with a signifigantly higher EV and a major edge over the "single player".
Collusion happens in live games. It happens in major cash ring games (just look at the current Mike Postle situation)-- there is simply no way it is NOT happening on every major poker network.
I highly doubt that the reputable
poker sites cheat themselves, but honestly who knows. Perhaps not the sites, but the sites admins/coders could easilly "back door" or provide superuser access to either themselves or people they know to consistently win.
I'm a winning live player- but I've found it basically impossible to really gain an edge online. Either you're up against maniacs shoving 73o against my pocket aces and catching two pairs, or getting killed on the river- it happens far more often then at a real table.
So online you're really up against two beasts: One is the Dishonest Players- who do exist. Secondly; you're up against a very erratic player pool- which is a difficult field to play period.
I play online for the practice. The stakes are so low in the small MTTs that losing a few hundred over a few months is less than one buy in at a $2/$5 live table...
That's my two cents.