Ironically it seems there is other people noticing the fraud cheats there too. Everything in a casino is recorded . It states in your club M rules only person registered to card is entitled to the benefits. Turn these people in and they will be prosecuted as sometimes the casino is just waiting until the dollar amount is big enough to actually charge them with more than a slap on the hands. It’s basically theft of services if they are not entitled to free comps on money they actually spent there. A few times by mistake using a card of someone else is no big deal . But if there is a pattern of constantly getting comps not entitled to them ,report them for investigation as the casino can look into the security cameras ect. It also has IRS complications as the casino is required to keep records of card use and there little party may end in a bang anyway . Watch for them and turn them ! (former casino worker) Good luck!