Ticket selling giant Ticketmaster is accused in a lawsuit of hacking into a rivals systems to use client information. The case involves a company called Songkick (which lets artists sell tickets directly to fans) and another company called CrowdSurge. These companies merged. Apparently, an executive for Crowdsurge was later hired by a company affiliated with Ticketmaster, and used customer information and access to CrowdSurge's systems to help Ticketmaster.
Ticketmaster claims that the information was never confidential in the first place, and that the claims have no merit.