Taylor Swift fans should be wary of online tickets, especially those that seem “too good to be true,” Minnesota Attorney General Keith Ellison warned late Sunday.

Taylor Swift will perform at Minneapolis’ U.S. Bank Stadium on June 23 and 24 as part of her Eras Tour. Scammers have apparently been exploiting high demand for her shows to sell fake tickets, cheating some out of up to $2,500 in other parts of the country, according to a news release issued by Ellison’s office. The Better Business Bureau has received almost 200 national complaints related to Swift’s tour, the attorney general said.

“Minnesotans who are defrauded by online ticket scammers should not have to endure a ‘Cruel Summer,’” Ellison said in the release. “Ticket scammers are nothing but trouble and what they do is illegal. I won’t stand by knowing there may be scammers out there trying to deceive Minnesota Swifties and other fans. If you believe you were taken advantage of, please contact my office to file a complaint.”

The attorney general’s office has not yet received any local complaints, though.

Although Ellison said buying second hand tickets is inherently risky, his office provided a few guidelines to help ticket buyers mitigate risk. For one, the attorney general recommended researching the ticket selling website to see if it is trustworthy. That could involve double checking the site is not a “spoof” website that mimics a legitimate ticket selling site.

Ellison also suggested making sure the website is secure by checking the URL. If it begins with “https,” it’s secure. Users can also look for a closed lock graphic in the browser, which is another indicator of a secure website. These two things generally ensure that users’ personal information cannot be accessed by others.

Finally, Ellison recommended purchasing tickets with a credit card. Often credit card companies provide zero fraud liability, meaning the credit card company will cover losses from theft or fraud after the cardholder reports fraudulent charges. This is a fairly standard practice with major credit cards like Visa, Discover, American Express, and Mastercard. But if the cardholder is not in good standing, they may not receive the same level of protection.

If someone thinks they’ve been scammed and is struggling to get a refund from their credit card company, the attorney general’s office can intervene and help mediate. But if the ticket was purchased with cash, a check, debit card, cash app, or gift card, there is little that can be done to get one’s money back, a spokesperson for the attorney general’s office said in an email.

To check the authenticity of the ticket, inspect it to make sure all the information, such as the date, time, and location, is correct. The ticket buyer can also call the venue to make sure the seat assignments exist.

“It’s our sincere hope that no one is scammed in Minnesota and that every Swiftie has the time of their lives at the Eras tour concert, but knowing that some fans in other cities [and] states have run into trouble, we wanted to alert Minnesotans to the possibility, and the possible remedies and safeguards, now,” a spokesperson told TCB.

Meet Minneapolis, the local visitors bureau, estimates that as many as 500,000 people are expected to visit the city for the Swift concert, Twin Cities Pride, and other events.