Experiencing some weird iOS 7 behaviour today? You're not alone - a number of users of the iOS 7 beta are reporting that their phones have bricked completely, forcing them to step back to iOS 6.
Apple is currently refusing to say what's happening outright, but it seems to be a case of cracking down on non-developers who have installed iOS 7 via a developer friend's account.
A lot of people reporting the problem had beta 3 installed at the time and others with later versions don't seem to be experiencing the same problem, so it could just be the third iteration that's programmed to lock phones down.
However some developers have also come across the same outage. If you're a developer, you can fix the problem by logging onto your devaccount and upgrading to the iOS 7 beta 6.