This expression is known to every experienced player in the casinos of Las Vegas and other regions of the United States, where gambling establishments operate.
Griffin Book is a large global blacklist of players who are not welcome in most American offline casinos.
It was made by the organization Griffin Investigations, which fights with sharpers and other scammers who trade in the gambling business. The Griffin Book includes the following people:
In «Black book» there are many players who have never been prosecuted because they have not formally broken the law. For example, American laws do not prohibit counting cards in blackjack, but gambling operators prevent this practice.
Casinos are not required to expel all the people listed in the Griffin Book, but most establishments prefer to deny them service because they pose a real threat.