[Mempho]

It happened to me almost 2 years ago on one of the major poker sites. The cheating idiot typed into the wrong chatbox (I suppose he was running an instant message program) and tried to cover it up. Anybody that tells you it can't happen is extremely naive. That said, I play online regularly but I won't touch the site where it happened because I have more fear that there are significant security issues there than at other sites.

One other thing, I was running a Sygate Personal Firewall at the time. I was not extremely adept at using it, though. I required every outgoing and incoming program to ask for access. I may have let something that looked innocent through or they could have gotten through the firewall.