Facebook’s (NASDAQ: FB) popular messenger service is at the center of a new lawsuit that alleges the social network monitors private messages and shares the data it mines with marketers.

Attorney Michael Sobel filed the lawsuit in a federal court in San Jose, Calif., on Thursday that alleges Facebook scans private messages including links to other websites to “improve its marketing algorithms and increase its ability to profit from data about Facebook users,” according to the LA Times. The information is allegedly shared with advertisers if the private messages contain a “Like” in them, along with a shared link.

The plaintiffs are hoping to turn the suit into a class action movement on behalf of all Facebook users that have sent or received a private message in the past two years.

Information Security Solutions firm High-Tech Bridge published a report in August claiming that private messages that included a link sent on Facebook’s messaging service could be used for potential robot spying.

Facebook told FOXBusiness.com it plans to fight the suit. "We believe the allegations in this lawsuit have no merit and we will defend ourselves vigorously," a spokesperson said in an email message.

FOXBusiness.com also reached out to the plaintiff’s attorney, Michael Sobel, for comment, but did not receive a response at press time.

According to Facebook’s posted terms of service, “We may enable access to public information that has been shared through our services. We may allow service providers to access information so they can help us provide services.”

Gant Redmon, general counsel for incident response software company Co3 Systems, says the lawsuit may hold up, although the federal statute it is relying on may be a bit of a stretch.

“This may gain traction with the FTC [Federal Trade Commission] because they go after anyone that is doing something with people’s information and not disclosing it,” Redmon says. “The No.1 thing the FTC loves to go after people for when it comes to privacy is a policy that doesn’t click with the actual use of personal information.”

Redmon describes Facebook’s privacy policy as long winded and it’s highly likely that individuals aren’t paying close attention to it when using the site.

“A lot of what the FTC wants is for you to say what you do, and do what you say,” Redmon says. “Behind these causes for action are often ‘did the person have a reasonable expectation of privacy?’ And when people send private communications, yes they do.”

Depending on the outcome of the suit, Facebook may move to alter its privacy policy, he says, to be more explicit in how they are gathering and using data.

He adds that the recent data and privacy breaches has shifted the way people behave online and that they have taken matters of privacy into their own hands.

“I do believe people will start to decide how they communicate and what they share, and find tools to stop other from seeing what they are doing,” he says. “These things do matter, but it comes down to that tipping point of ‘I am really upset about this, and want to maintain privacy.’”

Follow Kate Rogers on Twitter at @KateRogersNews