It's a great defense during a trial, but the cost would likely be associated with being arrested, loosing computer hardware to the local officers for an unknown amount of time, and the potential cost of mounting a legal defense in the first place.
I've always wanted to mount a big electromagnet in my doorframe like in Cryptonomicon.
The main reason I haven't is that there is a 100% chance I'd forget to deactivate it and fry my own hardware. Probably within a week of installing the magnet.
Well, yeah, but these are all memes wildly spread. Cryptonomicon (sadly) not so much.
I just think it would have been a nice gesture... 7 letters, not that much of an effort. Of course, it's not a crime, I wouldn't deem anyone a douche because they forgot to forewarn in the heat of discussion.
They should do a Curb Your Enthusiasm episode on this one :P
IANAL, but I believe the current code involves requiring the owners of the copyright to sue, and if the anime isn't held by a company engaging in suing foreign nationals...minor case..