Democrats on the Senate Judiciary Committee issued a firm warning to Ticketmaster on Thursday after Beyoncé announced her Renaissance World Tour: “We’re watching.”

Lawmakers have been eyeing Ticketmaster and parent company Live Nation since the debacle surrounding Taylor Swift’s hotly anticipated Eras Tour. Millions of her fans waited for hours to get their hands on tickets in November, but many were left empty-handed amid site glitches and opaque rules about how to register for presale access. Ticketmaster later canceled the general sale, apologizing but blaming what they called “unprecedented demand” for tickets.

Senators held a committee hearing last month after the firestorm, when lawmakers on both sides of the aisle grilled Live Nation’s president, Joe Berchtold. Ticketmaster and Live Nation were allowed to merge in 2010, but some have questioned if the company has been able to turn into a monopoly for ticket sales and touring.

“This whole concert ticket system is a mess — it’s a monopolistic mess,” Sen. Richard Blumenthal (D-Conn.), a member of the judiciary committee, said at the time.

Berchtold has argued Ticketmaster has an “obligation to do better,” but he rejected notions the broader company is a monopoly.

Demand for Beyoncé’s tour is already set to be off the charts. Live Nation said this week that the number of registrations (a prerequisite to have a chance to later buy tickets) “already exceed the number of available tickets by more than 800%” in some cities. Additional dates have been added in cities including Chicago, Los Angeles, Atlanta and Houston.

The full list of shows, which begin in Europe, can be found here.