Two Canadian law firms have filed a class action suit against the Toronto-based parent company of AshleyMadison.com, the infidelity site that suffered a massive hack last week, the Toronto Star reported.

The cyberattack exposed the full names, street addresses and partial credit card numbers of 1.2 million customers who had paid for the online dating service, and the lawsuit claims the privacy of thousands of Canadians was compromised due to the leak.

The only plaintiff so far is a disabled Ottawa widower who says he briefly used Ashley Madison after his wife of 30 years died last year, the Toronto Star noted.

"Unfortunately, my wife passed away of breast cancer last year. I was just looking for a little bit of company. But that was the extent of it. I sent a few emails. I never met a soul though," Eliot Shore, the widower, told the newspaper. "I'm not cheating on anybody."

The class action filed by law firms Charney Lawyers and Sutts, Strosberg LLP, meanwhile, is seeking $578 million in relief from Avid Dating Life and Avid Life Media, which run the dating website, Time detailed.

"Numerous former users of AshleyMadison.com have approached the law firms to inquire about their privacy rights under Canadian law," the firms said in a statement. "They are outraged that AshleyMadison.com failed to protect its users' information. In many cases, the users paid an additional fee for the website to remove all of their user data, only to discover that the information was left intact and exposed."

The Impact Team, the group of hackers that has claimed responsibility for the hack, meanwhile, is not named in the lawsuit, the Toronto Star noted.

"The subscribers were purchasing a service from Ashley Madison, and the main ingredient of the service was confidentiality and anonymity in using the website. That is the way Ashley Madison sold the product," Charney Lawyers' Ted Charney explained. "If they were not able to protect people and maintain their confidentiality, then in our opinion, they are liable for the privacy breach."