Don't type commands from the Internet, especially as root, especially when dd is involved. That being said,

If you're ever bored, from a TTY, type

sudo dd if=/dev/urandom of=/dev/fb0

This provides a nifty demonstration of how both the framebuffer and urandom works.

you can also take a sort of "screenshot" in a tty by typing dd if=/dev/fb0 of=./shot.fb

and then you can view it by flipping those filenames around, so that the shot.fb is now the input and /dev/fb0 is now the output.