Ticketmaster says it first identified the breach on May 20. Three days later, it identified that personal information may have been affected by the breach, which was the subject of Monday's email.

Ticketmaster has finally notified its users of a data breach — one month after Global News first reported that the personal information of Canadian customers was likely stolen.

Ticketmaster users across the U.S. are reporting instances of their tickets being transferred from their account and resold elsewhere without their permission.

Notorious hacker group ShinyHunters is claiming to have hacked Ticketmaster, stealing more than 500 million customers' sensitive data. Credit: Joe Raedle/Getty Images To its critics, it seems ...