Louis CK has a warning for would-be ticket scalpers: "We take great efforts and have many methods of finding out what inventory is being sold on broker sites like Stubhub and Vivid Seats and immediately invalidating those tickets," the comedian wrote on his website Tuesday, per the CBC. Some of the dates on CK's upcoming North American tour have already sold out; the comedian keeps his ticket prices at an average of $50 including all fees, he said in an email to fans that also went out Tuesday. His warning applies to both would-be scalpers and would-be buyers, because if they buy a ticket that's being re-sold and it gets invalidated, "the consumer could lose money and not get into the show," CK writes. (More Louis CK stories.)