Speaking of Slashdot, some fairly frequent poster had a signature back around 2001/2002 had a signature that was something like

mv /bin/laden /dev/null

and then someone explained how that was broken: even if that succeeds, what you've done is to replace the device file /dev/null with the regular file that was previously at /bin/laden, and then whenever other things redirect their output to /dev/null they'll be overwriting this random file than having output be discarded immediately, which is moderately bad.

Your version will just fail (even assuming root) because mv won't let you replace a file with a directory.