why did an fbi warning pop up?

[AC Question]

fbi warning screen and won't let me clear it or do anything, it's my nephews so i'm stuck and can't reboot or delete, please help...

 

[Golfdriver97]

I have heard of this before. You might have to get the ROM flashed again, but if you can't reboot the phone, there may not be much that you can do.