Took a picture and switched it over to attach the picture to text it to a friend and phone just froze with a black screen, I had maybe 2 other apps were running in the back at that time, these grey lines showing up on the black screen and it gets brighter and brigher until the whole screen was grey. I held the power button down and the 3 buttons at the bottom were flashing orange and the phone rebooted. everything is back to normal now but it was freaky.