Check your Facebook timeline.  Some users are reporting a security breach that hit Facebook today.  Private messages that were sent or recieved between 2007 and 2009 are appearing in users public timeline.

The temporary fix involves locking down your public timeline so everything is private until Facebook makes the corrections.  The step-by-step instructions are here, courtesy of our partner website KGAB.com.

UPDATE

The BBC reports that the problem affected a group of users in France.  Facebook counters that there was never a security problem and the messages have always been public.