Games where gambling is involved do run the risk of getting their players into trouble since gambling is illegal in the state of California. Luckily, for most people, playing poker amongst family members and friends is legal. It is when a poker game is run for profit by the host, then it becomes illegal.
Basically, not all states allow online poker to be played within their borders. However, due to US federal law (The Wire Act) that prohibits moving funds for gambling of any type over state lines, all the players in a poker game must be within the state.