French privacy watchdog dismisses reports of Facebook bug

Users did not realize the messages they posted on friends' Walls were public, and their visibility to all was not a bug, CNIL found

An investigation by the French privacy watchdog has found no truth to worldwide press reports last week that a Facebook bug was exposing old private messages to public view. Users had not grasped the public nature of the personal messages they were posting, and the "bug" was in their understanding of Facebook's privacy settings, the French National Commission on Computing and Liberty (CNIL) said late Tuesday.

French newspaper Metro reported on Sept. 24 that a Facebook user had discovered that what he thought were private messages from 2009 or earlier were now appearing in his public timeline. The newspaper reported that its staff had observed the same phenomenon in their accounts, and claimed a bug in Facebook's code was leaking private messages. As the news report was repeated worldwide, other Facebook users made the same observations and claims, forcing Facebook to issue a denial.

After an investigation lasting a little more than a week, CNIL agreed with Facebook, concluding that the problem was with users' memories, not with the social networking site.

The allegedly leaked data consisted entirely of messages from Wall to Wall, and none of the messages concerned had been sent via Facebook's private messaging system, the privacy watchdog concluded after compiling reports from numerous Internet users, and interviewing Facebook managers in France and elsewhere.

CNIL did not dispute the personal content of the messages appearing on the timeline.

However, it said, "The users had the impression they were sending private messages when they sent messages from Wall to Wall."

There were a number of reasons Facebook users might have been confused, it said.

For one, Facebook functioned differently before 2010 than it does today. In particular, Wall-to-Wall messages, while still public, were much less visible than today, and so users saw them as more private, CNIL said.

Facebook also unilaterally and repeatedly changed the privacy settings on user data between 2009 and 2010. At the time, CNIL and the other European Union data protection authorities that together form the Article 29 Working Group strongly criticized these changes, some made without users' knowledge. If users weren't vigilant, or if they accepted Facebook's default settings, then messages that had previously been private or accessible only by friends suddenly became available to anyone. And since the affected messages could be quite old, it was not always obvious to users that their potential audience had changed.

The recent introduction of the Timeline, a new way of visualizing messages and other activities on Facebook all the way back to the creation of the account, suddenly made these messages more visible, CNIL said.

While CNIL found that the recent discovery of these old messages was the fault of Facebook, but of its users, it nevertheless reiterated the calls it and other data protection authorities have made in recent years for social networks to take steps to protect users' privacy.

Those steps include being more transparent about their use of personal data; providing better tools for users to control the publication of their personal data; requiring users to opt in before activating new functions or passing their personal information to third parties, and making default privacy settings more protective of personal data, especially when unilateral changes are made to privacy policies or settings.

Peter Sayer covers open source software, European intellectual property legislation and general technology breaking news for IDG News Service. Send comments and news tips to Peter at

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