iOS 5.0.1 has bugs for FaceTime even under passcode locked phones
Those that have upgraded their device to the iOS 5.0.1 should definitely take good care of their devices, at least in the short while. This is because there is currently a bug inside the mobile operating system which allows anyone to access certain names inside the device’s phone book even when the phone is passcode locked as well.
This hack was discovered by Ade Barkah which stated that the exploit revolves around the Emergency Dialer feature on the iOS devices. To replicate the hack, users will just need to slide the locked phone to get to the passcode page. After that, click on Emergency Call and hold the home button for a few seconds to bring up Voice Control. Users can then FaceTime with any of the contacts through the locked phone.
Although this is anything but a serious bug, it may reveal some private information about the contact details of the person. This however, is a hit and miss method and requires the phone to be connected to a Wi-Fi network for FaceTime to be enabled. It should be noted that unless Siri is disabled, this hack will not be present in the iPhone 4S. although there are users saying that it is fixed in iOS 5.1 beta.