Intuit, Inc., the maker of the software used by TurboTax customers to file electronic tax returns stopped its e-filing return program in February after receiving notices from multiple states that thousands of fraudulent tax filings had been filed through the software, resulting in the theft of billions of dollars in fraudulent tax refunds.

TurboTax customers filed a class action lawsuit in California alleging that Intuit failed to safeguard their personal information, including Social Security numbers, which caused them to become victims of identity theft.

The complaint is based on Intuit’s alleged violation of the California Unfair Competition Law and Customer Records Act.

The Department of Justice, Federal Trade Commission and Congress are investigating the matter.