• Fans of Taylor Swift encountered a number of issues while trying to obtain tickets to the singer's latest tour via Ticketmaster.
• These complications have reinvigorated calls from activists and politicians for the Department of Justice to investigate the decade's-old merger of Ticketmaster and Live Nation.
• Ticketmaster and Live Nation have been accused of abusing their market power by hiking up ticket prices and adding arbitrary fees to purchases.

There's something about Taylor Swift and breakups.

Activists and lawmakers are renewing calls to split Ticketmaster and Live Nation after a fiasco over ticket sales for the pop superstar's upcoming "Eras" tour, which is slated to kick off in March.

Live Nation, which merged with Ticketmaster in 2010, has faced longstanding criticisms about its size and power in the entertainment industry. People amplified their complaints this week when tickets for Swift tickets went on presale on Ticketmaster's website. The company was forced to extend presales after fans flocked to the site, causing site disruptions and slow queues.

Ticket buyers immediately turned to social media to complain after the website appeared to crash or freeze during purchases, leaving many unable to get tickets for the show. Some users were shown an error page stating, "We're sorry! Something went wrong on our end and we need to start over. Broken things are a drag — our team is on it so it doesn't happen again."

Lawmakers are also calling on the Justice Department to investigate the company.

"Daily reminder that Ticketmaster is a monopoly," Rep. Alexandria Ocasio-Cortez, D-N.Y., wrote in a Tweet Tuesday. "Its merger with LiveNation should never have been approved, and they need to be reigned in. Break them up."

Similarly, Sen. Richard Blumenthal, D-Conn., called Swift's tour sale "a perfect example of how the Live Nation/Ticketmaster merger harms consumers by creating a near-monopoly," in a Tweet posted Tuesday.

"I've long urged DOJ to investigate the state of competition in the ticketing industry," he added. "Consumers deserve better than this anti-hero behavior."

Representatives from Live Nation did not immediately respond to CNBC's request for comment.

Others complained about the long wait times and confusion over "verified fan" tickets and presale codes. The verified fan program, which was established in 2017, was designed to keep tickets in the hands of actual fans and not resellers.

But, that didn't appear to work in several cases. Within hours, tickets for the tour were already up for sale in the secondary market at exponential markups.

"Eras" tour tickets are priced from $49 to $450, with VIP packages starting at $199 and reaching $899. Secondary market prices can be seen ranging from $800 to $20,000 per ticket.

"The [Taylor Swift] portal is not going well for many Swifties," Rep. Bill Pascrell, D-N.J., wrote in a tweet Tuesday. "I'm hearing about site crashes and fans waiting for hours. You'd think all these service and convenience fees could go to a working website."

Activists have accused Ticketmaster and Live Nation of abusing their market power and called for the company to be broken up.

"Despite promises of increased competition and consumer benefit, they now control 70% primary ticketing and live event venues market," according to a coalition of activists called "Break Up Ticketmaster." "They're hiking up ticket prices, charging rip-off junk fees, and exploiting artists, independent venues, and fans. The Department of Justice can reverse this merger and bring competition back to the industry. Help us demand that they do."

Swift's latest tour, which comes on the heels of her record-breaking new album release "Midnights," has set 52 dates so far, the singer's largest tour to date. The "Eras" tour could break Swift's own record for gross ticket sales in North America.