Since the casino opened last year, a number of fight videos have been posted online, but representatives of the casino say such incidents remain a rare occurrence."The overwhelming majority of the 5 million-plus visitor who have enjoyed the casino since it opened 14 months ago have done so responsibly and in the spirit of fun," the casino said in a statement to the media. "In the rare instance when this occurs, we follow a zero-tolerance policy."The casino said the individuals involved have been issued lifetime bans. But it was unclear whether anyone had been arrested.