According to the TimesOnline, the chief of British intelligence agency MI6 was outed from his cover-name by his wife, who posted to him affectionately on Facebook wall using the moniker, "C".
Sir John Sawers, the agent in question, was poised to be installed as chief in November, and his wife's breach of security--her profile was open to all Facebook's 200 million members with no privacy settings enabled--will set back the the transition considerably. Sawers' wife also posted photos, information about friends and family, vacation spots, and other potentially sensitive details on Facebook. (Image of Sawers from Facebook, below, courtesy of TimesOnline.)
As one member of parliament pointed out, having that kind of information publicly available opens Sawers and his family to blackmail. Another MP put it more bluntly: “This type of exposure verges on the reckless. The prime minister should immediately commission an internal inquiry as to whether this has breached the security of the incoming head of MI6 too seriously to allow him to take up the post.”
To us Americans, the scandal comes as mere confirmation that yes, indeed, the single-consonant code-name scheme we learned about in James Bond films is still intact at MI6.