Ashley Madison, a dating website targeting married people, was breached by hackers, exposing the information of millions of its customers, site ownerAvid Life Media confirmed.

In a statement released Monday on the Ashley Madison site, Avid Life Media says they were flagged on an unauthorized attempt to gain access to their systems. The company says sites have since been secured.

“We are working with law enforcement agencies, which are investigating this criminal act,” says the company in a statement. “Any and all parties responsible for this act of cyber–terrorism will be held responsible.”

Avid, which also runs dating sites CougarLife and Established Men, did not say what data was compromised as a result of the breach. According to the blog Krebs on Security, the company’s “user databases, financial information and other proprietary information” were affected.
In a later statement, the company says it used the Digital Millennium Copyright Act to remove posts related to the breach and any personal information posted online.

Between its three websites, Avid boasts a combined 40 million members.

Two months ago, dating site AdultFriendFinder confirmed it fell victim to a data breach, compromising personal data including email addresses, dates of birth and sexual preferences for more than 4 million users.