Privacy groups have filed complaints with US regulator the Federal Trade Commission (FTC) over Facebook's latest privacy changes.
The Electronic Privacy Information Center (EPIC) claimed in a statement that it had been joined by nine other privacy organisations in requesting the FTC to investigate recent changes to Facebook's privacy settings.
Since the changes were made, Facebook has been criticised by groups such as the Electronic Frontier Foundation, the American Civil Liberties Union and EPIC for encouraging users to share more information than they had previously.
Users were met with a privacy transition tool after the changes took place earlier this month, advising them to share their social networking content with everyone on the internet rather than the previous default, which was limited to a user's networks and friends.
"This is the most significant case now before the FTC," said EPIC executive director Mark Rotenberg,
"More than 100 million people in the US subscribe to the Facebook service. The company should not be allowed to run down the privacy dial on so many American consumers."
Facebook could not immediately be reached for comment, but reports have said that the firm supposedly cleared the changes with the FTC before making them.
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