It seems that giant octopuses don't just attack sharks. Salmon researchers off the west coast of Vancouver Island in Canada caught video of a giant octopus attacking their remotely controlled mini-sub. Although the octopus was huge and the submarine virtually defenseless, the mini-sub managed to escape unharmed by using its thrusters. (I know you were worried...)
In light of this attack, I renew my call for a cessation of hostilities between humans and octopuses. We won't treat you like sushi if you stop eating our subs.
Thanks to Al for the tip.