(CBS NEWS) — Ashley Madison, a controversial online social network that gears itself towards married people seeking to have affairs, has been hacked, and the company that owns it is being threatened with exposure of users’ personal information.

Hackers have threatened to reveal customers’ sexual fantasies and financial information if the website is not shut down, according to the Krebs on Security, an online cyber-security information site.

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CBS News business analyst Jill Schlesinger said in an appearance on “CBS This Morning” that 37 million people use AshleyMadison.com. The site is owned by Avid Life Media, which has confirmed the hack.

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Use of the site is largely free, but there are several features (such as chatting) that cost extra. For example, registered users may elect to pay an extra $19 fee to get their data scrubbed.

The company has collected millions offering the service, but the hackers are claiming that this scrubbing is not occurring. Schlesinger reports the hackers want the website shut down.

The hackers appear to be engaging in blackmail, but their exact reasoning is unknown.

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