After a rocky IPO, Facebook finally had a good day on Wall Street, with the company's stock recording its largest single gain on Wednesday. The optimism among investors was apparently due to a positive quarterly earnings report. But the traders must not have read a story earlier this week in the Washington Post, which suggested that Facebook is facing some backlash in the form of a lawsuit from European users concerned about its commitment to consumer privacy.

The Post profiles the quest of an Austrian law student, Max Schrems, to find out how much data Facebook is retaining on its users—and whether hitting the delete button really means that information has been permanently expunged.

Schrems was motivated to contact European regulators when he found out that the data held on him by Facebook—when brought in to a non-digital medium—ran to no less than 1,222 pages.

Pictures uploaded from smartphones included precise global positioning system coordinates, the identities of anyone tagged in the photos and the moment — down to the second — when the shutter clicked. Information that users thought they had deleted survived in Facebook files.

Based on the documents, the German newspaper Taz made a diagram of Schrems’s social life, with distinct clusters around different phases — his time as an exchange student in the United States, his stint as a volunteer with an ambulance corps, his current life as a law student living in an apartment in Vienna.

“That’s basic FBI stuff,” Schrems said. “Thirty years ago, you [would] put up a pin and look for the connections. Now you know in a click.”

Americans are known as rugged individualists, with a right to privacy now assumed to be written between the lines of our Constitution. But it's Europe that has more robust rules on such issues. And Schrem is taking full advantage of these strict privacy laws as he raises money to take on Facebook in court.

It's no surprise that the old world is more sensitive to privacy issues. For at least some Europeans, memories of domestic surveillance by Stasi-like regimes are relatively recent. Older generations can remind younger ones of the horror of finding one's life summarized in a file compiled by strangers.

Facebook, of course, is no Big Brother. After all, users freely sign up and agree to give away personal data to the service. But they might consider more carefully what their role is in the transaction. What seems on the surface to be a "free" service is really paid for by turning over information that is valuable to advertisers. As some have put it, to Facebook executives, "you are the product, not the customer."

This cold economic reality is hard to swallow at a time when the Internet is still held up as the world's great equalizer and promoter of liberal democracy. Yet the powerful social experience provided by Facebook comes at a cost. And many users will reject Schrem's concerns and feel no hesitation at handing over a profile of intimate details to unknown parties.

Facebook is banking on it.