Last night my phone went black while it was idle in the car, plugged into the charger.
The screen vanished. I tried to start it but it stayed black for about an hour.
Finally it started on it's own with a robot icon that said "erasing". There was very small blue and red lettering across the top of the phone screen that came on so quickly and then vanished.
Then the phone went to the Verizon logo.
When it came back on, everything was changed. The background photo was replaced by the stock logo and all apps were gone, as well as all contacts, pictures, notes, videos.... everything!
