An Apple exec has a tip for preventing a thief from unlocking your iPhone X with your face

If anyone tries to steal your new $999 iPhone X, Apple has a simple word of advice: squeeze. 

That's the recommendation from Apple SVP of Software Engineering Craig Federighi when asked about the risk that the iPhone X's facial recognition system could make the device easy prey for thieves. 

The new iPhone, which will be available November 3, comes with a feature Apple calls FaceID that lets consumers unlock their phones by simply holding the phone in front of their face. Many observers were quick to point out that the system, while undeniably cool and handy, could make it easy for someone other than the owner to unlock a phone - they could potentially just point it at the owner's face.  

One prospective customer emailed Federighi to ask him about Face ID possibly fatal flaw.

"What will prevent a thief from taking my phone, pointing it at my face, and running?" asked Keith Krimbel, a freelance video editor.

A few hours later, Federighi responded. In an email, which Krimbel posted on Twitter, Federighi offered the following advice:

"There are two mitigations: If you don't stare at the phone, it won't unlock. Also, if you grip the buttons on both sides of the phone when you hand it over, it will temporarily disable FaceID."

Here's the full exchange:

Nerves of steel

The closed-eyes defense was already known, as Apple execs had suggested as much during the iPhone X unveiling on Tuesday. Officials noted Face ID "needs your attention" to unlock a phone.

But Federighi's tip about griping the buttons on both sides of the phone is new. 

Whether it actually works as a safeguard from muggers and miscreants however may depend on the coolheadedness of the victim. If you're the type of person who can keep calm and remember to surreptitiously press opposing buttons on a phone while being threatened by a mugger, then you'll be fine.  Or at least, the person who took your phone won't be able to access your data.

If you don't think you'll have presence of mind to disable FaceID in the heat of the moment, you can always just close your eyes.