Gizmodo's Kashmir Hill continues her excellent investigative work on Facebook's mysterious "People You May Know" system, which has caused consternation among users by making seemingly impossible (and often disturbing) connections, such as "A woman whose father left her family when she was six years old—and saw his then-mistress suggested to her as a Facebook friend 40 years later." Read the rest “Facebook's "shadow profiles": the involuntary dossiers of information you never provided, and can't opt out of”