Hackers have targeted Ticketfly, forcing the Eventbrite-owned ticketing service to temporarily go offline. The move affects both Ticketfly’s own website and the sites of venues hosting on its servers, including Brooklyn Bowl, Merriweather Post Pavilion, the 9:30 Club, and more. Those sites currently return a “502 bad gateway” error. Earlier today, the sites featured a message from the hacker, threatening a data leak.

In a statement, a Ticketfly spokesperson wrote, “We’ve determined that Ticketfly has been the target of a cyber incident. Out of an abundance of caution, we have taken all Ticketfly systems temporarily offline as we continue to look into the issue. We realize the gravity of this decision, but the security of client and customer data is our top priority. We are working tirelessly to get our clients back up and running.”