playing without knowing more about the rules concerning exposing cards might jeopardize you. Most card rooms and tournaments directors agree that unrestricted showing of cards is unacceptable, and one exposes to another, he must show them to everybody. It refers to a case when someone has seen an online casino player show his hand to another player who presumably has folded is "show one show all". This clearly means that if the online poker player gave information to an opponent; he also has to give to the other ones. Anyway, this rule has been met with many professional players; one of them is Daniel Negreanu, who spoke about that phenomena and was opposed to this rule.