Facebook is under investigation by the Federal Trade Commission over the use of personal data of 50 million users by a data analytics firm to help elect President Donald Trump.
The FTC is probing whether Facebook violated terms of a 2011 consent decree of its handing of user data that was transferred to Cambridge Analytica without their knowledge, according to a person familiar with the matter.
Under the 2011 deal, part of a settlement of federal charges that it forced consumers to share more personal information than they intended, Facebook agreed to get user consent for certain changes to privacy settings.
Spokesmen for Facebook and the FTC didn't immediately respond to requests for comment.
If the FTC finds Facebook violated terms of the consent decree, it has the power to fine the company thousands of dollars a day per violation.
Facebook declined in New York trading, falling 3.2 percent to $167 as of 9:31 a.m. in New York. That follows a drop of 6.8 percent Monday.
The Facebook revelations have also prompted bipartisan, transatlantic concern. The Senate Commerce Committee announced Monday evening it would like a briefing on "the use and sharing of individual Facebook user data."
The chairman of a U.K. parliamentary committee announced Tuesday he was requesting that Facebook CEO Mark Zuckerberg, who has remained silent for days, appear before the panel to supplement prior testimony by the company's executives.
Republican lawmakers, who normally resist regulation of private business, started coming down on the company as early as Sunday, with Senator Jeff Flake of Arizona calling the privacy violations "significant" and Senator Marco Rubio of Florida saying he was "disturbed" by many things about the company.
-- Bloomberg News