Austrian campaigner Max Schrems billed it as a David Vs Goliath lawsuit against the giant claiming damages of €500 (£397) per supporter for alleged data protection violations, including over the US Prism spy programme.
In what could be the largest class and privacy action taken in Europe, angered users are being asked to sign up on an app on fbclaim.com.
"We are only claiming a small amount, as our primary objective is to ensure correct data protection," Mr Schrems said. "However, if many thousands of people participate we would reach an amount that will have a serious impact on Facebook."
The lawsuit is being taken in the Commercial Court in Vienna against the Irish subsidiary of the New York-listed web giant.
Mr Schrems, a privacy activist, has more than 20 complaints of alleged data breaches involving Facebook filed with the Irish data watchdog.
The action in Vienna claims Facebook Ireland is in breach of European law on users' data and that it violates rights by tracking internet use on external sites.
It attacks Facebook's analysis of users through what it calls "big data" systems.
Mr Schrems claims the company supports the US Prism surveillance programme, the National Security Agency's secret monitoring and data mining exposed by whistleblower Edward Snowden.
Facebook declined to comment.