I saw them all on
www.bash.org and
www.bash.cx before (excellent quote sites).
The top one seems to be a lot of bullpoop though - sounds very fake to me. Yes, copper is conductive, but that shouldn't matter. There aren't any conductors touching the case, and in fact most cases aren't isolated internally. Knocking the power out in the whole house would imply there was a short on the mains/AC line, which only goes into the PSU (where it is regulated to lower voltages), and does not touch the case.
I just realised I used my geekiness to spoil an otherwise funny quote :-/