Sign in from enough new places and Facebook will lock your account. Not for anything more suspicious than travelling - just for being in one place one day and another the next. My credit card company used to be like this; they promoted a credit card designed for travellers with no extra commission charges for using it abroad - and then expected people to phone up and say they'd be travelling. Over time they invested in proper fraud evaluation technology and now I only need to phone if something goes wrong; the default is they do the job of evaluating risk rather than making the customer jump through hoops. Facebook is still laying out hoops; it's locked my account twice this trip already, once for arriving in LA and once for arriving here in New Orleans. I appreciate the concern, Facebook, but how about you switch to a more sophisticated risk evaluation system - or give me an 'I travel' checkbox so I don't to unlock my account every 10 days?