Senate Warns Ticketmaster Over Beyoncé Tour Ticket Sales After Taylor Swift Fiasco

Ticketmaster is firmly under the U.S. Senate's microscope as the ticket giant prepares to sell tickets to the upcoming Beyoncé tour ... and it's all because of the Taylor Swift disaster.

The Senate Judiciary Committee, which just got finished grilling Ticketmaster's parent company Live Nation, issued a thinly-veiled warning Thursday, the day after Bey announced her "Renaissance" world tour.

The committee's official Twitter account tagged Ticketmaster in a quote tweet for a CNN story about Beyoncé fans preparing for another potential Ticketmaster fiasco, saying ... "We're watching, @Ticketmaster."

Ticketmaster says they're making changes -- staggering sales and using Verified Fan technology -- for the Beyoncé tour after running into major issues with last year's rollout for the Taylor Swift tour, which pissed off Taylor and her fans and led to lawsuits and Senate hearings. Still, the Senate will be keeping a close eye on the process.

Sen. Amy Klobuchar, who grilled Live Nation execs during the recent hearings, told us on "TMZ Live" the Senate expects Ticketmaster to do better in the future.