New lawsuit targets Facebook over privacy

A new US lawsuit, is demanding Facebook pay up to $US10,000 to each user whose privacy has allegedly been breached by advertisers.

A new lawsuit that consolidates several complaints about Facebook's privacy policies has been filed in California, seeking damages for US users of the social network for improper tracking.

The class action alleges that Facebook was improperly tracking internet use of its members even after they logged out of their accounts.

It consolidates 21 related cases filed in more than a dozen US states in 2011 and early 2012.

The filing came as Facebook had its market debut with a record public offering worth $US16 billion, valuing the world's biggest social network at about $US105 billion ($A106.54 billion).

The lawsuit seeks up to $US10,000 for each Facebook user, or more than $US15 billion in total.

"It's not a pipedream," attorney Billy Murphy of Baltimore, Maryland, told AFP.

"The only way you are going to stop companies from disregarding the privacy rights of the American people is to take some of their money. That's the only thing that gets their attention."

But some consumer and privacy advocates say Facebook has been too loose with data from its 900 million users around the world, and hope that as a publicly traded company it may change its tune.

Facebook has been bedevilled by privacy complaints and had its knuckles rapped over the issue by both US and European authorities.

The social networking giant's co-founder Mark Zuckerberg has repeatedly apologised for privacy lapses amid outrage from users over revelations their online activities were visible to a wide audience of advertisers and other users.

Late last year, in a settlement with the US Federal Trade Commission, Facebook promised to honour users' privacy preferences and to stop making claims about the security of personal information that are untrue.

That deal settled two-year-old accusations that Facebook had allowed advertisers access to the community's personal data when users were told it was being kept private.