It can definitely be manipulated by the poker room in many ways, if that's their goal.
They can introduce bots, tamper with the poker code, changing the probabilities for certain outcomes to, for example, favor more aggressive players, or staff players disguised as regular clients. These staff players, or even known pro poker players hired by the poker room to attract more people to join in, could also be able to see the other players
hands, like supposedly happened in Ultimate Bet, which they used to call "God Mode" (if I remember correctly), etc.