Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_5 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8L1 Safari/6533.18.5)
Sounds like the mobileme keychain sync bug. How many of you people with this problem use mobileme for syncing?
I've seen it as an iOS developer. I sync my keychain to mobile me on my mac, then when i install an update of my app, it bricks the phone due to a mismatch of some keychain data. Evidently it makes iOS think that it's being jailbroken, so it goes into lockdown.
That could be the case here, since facebook probably relies on stored credentials for its HTTPS encryption.
Either way there is NO WAY this is facebook's fault! Apple's OS should never do this, ever, no matter how crappy an app may be. It should never ever do this.
This is 100% Apple's fault!