The data on an iOS 4 device is encrypted using a key that's derived from your 4-digit passcode, meaning there's only 10,000 possible encryption keys.

Many of us use the same 4-digit code for everything. Phones, credit cards, and even padlocks. A new report has shown that millions of people are using identical PIN codes, making phones and bank ...

As it turns out, you really should use FaceID or TouchID to access your phone because if anyone gets a hold of your passcode, it's really bad.

How to Stay Protected In a tweet, Stern recommended that users switch from a four-digit passcode to an alphanumeric passcode, which would be more difficult for thieves to spy on.