I mean, a lot of justifications I've seen for what they're doing are based around legal arguments (some would say loopholes). I'm actually more interested in the ethical side of things. Why is making it easy for people to steal ethical?.

Because there are plenty of examples of ethical (but not necessarily legal) uses of The Pirate Bay/bittorrent:

1) A TV show is shown on the BBC. I've paid my TV licensce. Ethically I can download it and watch it.
2) I've just bought a game and don't want the DRM crap. I can ethically download the DRM free version (especially seeing as I can't get a refund these days).
3) I left my favourite CD at home, and I'm on holiday. Ethically I can download the music I paid for to be able to listen to it.
4) I just bought a DVD but can't be assed to rip it... someone online has done it for me. I can download that copy ethically.
5) I'm downloading a linux disto, some creative commons films or any other media that the author *wants* people to share. Ethical.

Please explain why I shouldn't be able to sleep at night doing these things, other than the fact that I might go to jail for doing them and I hear the beds aren't that comfy there.

R2-45

Not to be confused with RJ-45.

Woah, I've got to be much more careful when terminating CAT-5...