Over at MacRumours, they have reported the existence of a bug in iOS 6.1 (and also in earlier versions of iOS) that allows for someone (malicious or not) to gain access to your phone despite a passcode lock. This bug allows for phone and contacts access and does require correct timing to pull off correctly. For transparency sake, here is how to replicate the bug:
1. Lock device
2. Slide to unlock
3. Tap emergency call
4. Hold sleep button until the power down prompt shows. Click cancel, you will notice the status bar turn blue. Type in 911 or your emergency number and click call then cancel it asap so the call dosen’t go through.
5. Lock your device with the sleep button then turn it on using the home button.
6. Slide to unlock then hold the sleep button and in 3 seconds tap emergency call. This will spazz out the phone and cause it to open.
[Make sure to continuously hold the sleep button until you are done looking in the phone]
This is definitely not a new bug in the least and Apple have usually been quick to act on these security flaws on their devices.
disclaimer: Please don’t attempt this too many times as the mistiming may cause your emergency call to be sent to the operators clogging up the line.