Isn't it trivial for online poker providers to cheat, i.e. manipulate the cards you receive, and have a fake bot player at the table that can be made to win, etc. ?
Long term, people store their hand histories and this shows up plainly in analysis.
The server knows what cards everyone is holding. Even if the cards were randomly assigned and weren't changed after the fact, users have no logs of the order of cards remaining in the deck. Its pretty trivial to have software that selects community cards that usually lead to a larger pot.
The much simpler way to cheat is to just give some players more information. Or, run bots that take up guaranteed payout seats in tournaments and such, which I've heard rumors of happening on certain sites. Or both.
And yes, both the types of cheating you've mentioned have happened.
Some players getting more information is called "superusing" -- see Absolute Poker scandal.
Empty seats being filled with bots in tournaments with a guarantee -- ACR
My point was simply that an online casino could seem completely legit even if you can compile audit logs of every players' hands at the table. Controlling the community cards is completely undetectable and more than enough to push larger pots, and therefore larger rakes.
Most pots already hit maximum rake.
As far as I'm aware, you would have to know the full list of cards in the shuffled deck before the hand was played to know they didn't change the community cards.
The community cards are subject to the same frequencies as the hole cards.
(And you can see them more often, so they're actually easier to analyze)
On the other hand, that still doesn't prevent cheating in the form of the server providing information to some participants via a different channel. There's nothing cryptography can say about out-of-band communications.
So maybe fair shuffling is cute but ultimately pointless.
Doubtless there are scummy poker games, but for most of them the money comes plenty easy, and the existential risk of faking cards to increase pot sizes just isn't worth the marginal benefit.
Of course everyone, winners, losers, and impartial bystanders will see these patterns in completely random deals so every site will be accused eventually.