Do we really know that online poker is on the level? I.E., not rigged

[ColdCaller]

PokerStars will offer to send you your entire hand history at any time for personal auditing reasons in PT-compatible text files.

If there is statistically valid deviation from the mean in ANY respect, you will know if there are problems.

I can't say if Party makes the same offer (lol), but I've had my hand histories sent to me from PokerStars a few times (well over 100,000 hands).