I was just using my phone, when the network dropped out completely. I rebooted, but it just wouldn't connect.
When I toggled airplane mode, it asked me for my network unlock pin (my device is SIM-locked to the provider) - I had already had my device unlocked.
Luckily, I was able to use an app to get my unlock code.
Has this ever been reported to have happened before? How did this happen?