Ashley Madison lawsuit
A detail of the Ashley Madison website on August 19, 2015 in London, England. Hackers who stole customer information from the cheating site AshleyMadison.com dumped 9.7 gigabytes of data to the dark web on Tuesday fulfilling a threat to release sensitive information including account details, log-ins and credit card details, if Avid Life Media, the owner of the website didn't take Ashley Madison.com offline permanently. Getty Images

Two Canadian law firms have filed a $578 million class-action lawsuit against the parent companies of adultery site Ashley Madison, after hackers leaked the personal information of its users online this week.

The firms, Charney Lawyers and Sutts, Strosberg LLP, said Friday that they filed the suit on behalf of Canadians whose private information had been released in the hack. The suit targets Avid Dating Life Inc. and Avid Life Media Inc., the Toronto-based companies that run AshleyMadison.com.

"The sensitivity of the information is so extreme and the repercussions of this breach are so extreme, it puts the damages faced by members in a completely different category of class-action suits," lawyer Te Charney told the Associated Press (AP).

The Canadian lawsuit is not the only legal action the company is facing over the leaking of its customers' data. Lawyers in Missouri have filed a class-action lawsuit against the company, with the lead plaintiff being an unnamed woman who reportedly paid a $19 fee to the website in order to permanently scrub her data from its servers, a so-called "paid delete."

Experts have offered conflicting opinions on the likely success of legal actions brought against Ashley Madison and its parent companies in the wake of the breach.

In most data breach cases, the plaintiff's biggest hurdle is proving that the users suffered a tangible harm. "Here, unlike most retail breaches, just the fact that one is exposed as a customer of the site is sensitive, confidential, and potentially damaging information," Goodwin Procter partner Brenda Sharton, who chairs the firm's privacy and data security practice, told the Verge.

Other experts, however, suggested that the fact that potential plaintiffs would have to effectively out themselves as customers of the site, would discourage people from coming forward.

"I'd be surprised if you get a lot of traction here," Scott Vernick, a partner and head of the data security and privacy practice at the law firm Fox Rothschild LLP, told the AP.

The FBI and Canadian law enforcement agencies are investigating the hack that resulted in the breach of users' data. The hack was reportedly carried out by a group that calls itself The Impact Team. The hackers cite the company's data practices and the immorality of extra-marital affairs as reasons for their actions.

The group released a second trove of data from the site this week, which included emails sent by Noel Biderman, founder and CEO of AshleyMadison.com’s parent company Avid Life Media.

AshleyMadison.com, which has the slogan “Life is short – have an affair,” reportedly has over 30 million members worldwide.