Ticketmaster is notifying millions of customers about a data breach that could be one of the largest in North American history. Ticketmaster said on its website that “customers can continue to conduct business with Ticketmaster as normal and without issue.”“Our comprehensive investigation — alongside leading cybersecurity experts and relevant authorities — has shown that there has been no more unauthorized activity. According to the notice to customers, data began being accessed on April 2 and continued until May 18. “We have not seen any additional unauthorized activity n the cloud database since we began our investigation,” according to the notice. “They should also change their password on any other account where they’ve used the same or similar password to the one on their AT&T account, a practice that should be followed during any data breach.