Alert — if you resold your Taylor Swift tickets you bought on Ticketmaster, you may be on the hook for the profits. Ticketmaster has turned your info over to the IRS already, thanks to a new law, and:

The average price for Taylor Swift tickets sold in the U.S. on StubHub was $1,095, with the best seats going for thousands of dollars, according to the company, which operates an online market for people to resell and buy tickets.

Also, the number of fan resellers skyrocketed.