California's attorney general disclosed an ongoing probe into Facebook's privacy practices Wednesday, as it sued the company over its repeated refusal to turn over documents and answer questions.
California Attorney General Xavier Becerra said his probe has been going on for more than a year. He said he was disclosing it now because his office was making a public court filing to force the company to comply with subpoenas and requests for information.
"Facebook is not just continuing to drag its feet in response to the Attorney General's investigation, it is failing to comply," the lawsuit said.
The lawsuit was filed in state Superior Court in San Francisco.
The California probe, one of many legal and regulatory inquiries into Facebook, began as a response to the Cambridge Analytica scandal and grew into an investigation into whether Facebook misrepresented its privacy practices, deceived users and broke California law.
Cambridge Analytica, a data mining firm, gathered details on as many as 87 million Facebook users without their permission. The Federal Trade Commission fined Facebook $5 billion this summer for privacy violations in an investigation that also grew out of that scandal. California officials say questions have been raised about what Facebook knew and why it didn't prevent third parties such as Cambridge Analytica from misusing user data.
The court filing said Facebook hasn't given answers on 19 of the attorney general's questions and hasn't given any new documents in response to six document requests. The filing also said Facebook has refused to search the emails of top executives Mark Zuckerberg and Sheryl Sandberg, as the state requested.
Becerra's office said it requested additional information after Facebook took a year to respond to an initial subpoena.
Investigators sought communications among executives on developers' access to user data, the relationship between ad spending and access to data and the introduction of new privacy features and privacy-related news stories. Officials also sought information on the effects of privacy settings on third-party access to data and Facebook's enforcement of policies.
Facebook, which has its headquarters in Menlo Park, California, didn't respond to requests for comment.
California hadn't joined a separate probe involving attorneys general from New York and other states. The New York probe is looking into Facebook's dominance and any resulting anticompetitive conduct. California is also a holdout in a separate probe into Google's market dominance.
The District of Columbia and Massachusetts have also gone after Facebook on privacy. The Massachusetts attorney general's office is set to argue in a state court Thursday why Facebook should be compelled to stop resisting and turn over documents for its investigation.
Facebook's various legal troubles have yet to make a significant financial dent on the company. Even the FTC's $5 billion fine, the largest ever for a tech company, came to just under one-tenth of Facebook's revenue last year. The penalty was criticized by consumer advocates and a number of public officials as being too lenient.
AP Technology Writers Mae Anderson and Frank Bajak contributed to this report.