I found an utterly fascinating story about what seems to be a provable case of large-scale (6 figures) cheating in online poker. The best thing about this (apart from being a ripping yarn about software security) is that the detective work has been done by members of an online forum, and all their guesses and investigations and allegations can be seen, step by step.

I started from a blog post by Bruce Schneier, which linked to a few summaries, which in turn linked to links that led to links that led to links… as much information as you could possibly want.