For the first time time ever, I was presented with this screen earlier today: I had never encountered this screen… on this or on any previous iPhone. "After 48 hours of what?" is a logical question. I found some insight on Apple's "About Touch ID security" page, which states: However, more than 48 hours had not elapsed since the previous time I had unlocked my device. I unlocked and used my device plenty late last night. Is this a bug, or did I unwittingly pass through some kind of time warp?