There are many urban legends out there talking about
n00bs asking a *nix related question and getting the answer
just do rm -rf / from the terminal (by the way, you don't want to do that - it tries to recursively erase all the files from your hard-drives - in general when you get advice from a website, you really should corroborate the advice with the documentation).
Anyway, back to the story: I was sitting beside a sysadmin friend and we needed to kick out some processes connected to the machine, so that we can change port bindings and all that stuff. I don't know why, but instead of doing netstat -anpt and then killing off the processes connected, I suggested doing rmmod ipv6. This can't hurt since, we're connected through IPv4, right? And when it refused, said the module was
in-use I said
surely there must me a force switch.
And indeed there was. And the network connectivity went away. And we had to task someone from that building (this was all going on through SSH, over several hundreds of kilometers) to go and reset the machine. Surprisingly (or maybe not) the same night the box developed a filesystem corruption and caused a couple of hours of outage.
So there you go: rmmod -f ipv6 is the new rm -rf /.