secure-delete* package name in debian (sdmem: secure-delete memory)
Wipe mode is secure (38 special passes)
Using /dev/urandom for random input.
Wipe mode is insecure (one pass with 0x00)
Happen to me, i opened xfce-terminal and start moving it right and left until the screen freezed permanently (play for less than 3 minutes with anything like browse some stuff and open close terminal…).