You could tell them to get lost just like I could in Canada. But it doesn't mean your ISP won't cut you off. It's the ISP that has to either provide them your email address or forward the note. If your ISP provided NBC (for example) with your email address, then I'd dump them anyway. That's more unethical than the download.

Most people who receive notices (I've received two in the past 5 years) do so because they're uploading content. In both instances the content in question was some crap file that I had simply forgotten to delete. Whenever I need to grab a show now, I remove it from the program I'm using to download as soon as it's finished. Yes, that's somewhat against the spirit of the P2P sharing principles, but I'd rather not get snooped and sent emails.

This is all possible because your IP is visible.

Anyway, I grabbed missing episodes of two cancelled shows and one cartoon that gets spotty timeslots here in Canada. Watched them and then deleted them (as I had no reason to keep them around). Morally and ethically the download and watching is, IMO, exactly the same as having watched them on TV as I would have recorded them with my PVR. The difference comes in the timespan where you're actually seeding the content to others. That distribution would never be a part of your normal TV/PVR watching experience. Unfortunately withotu someone uploading, no one can download. So someone has to be violating the spirit/laws, even if we feel justified in watching.

I intend to buy the cartoon I watched on DVD (all seasons) as soon as they're available. If the remaining episides for one of those shows ever make it out and wrap the show, I'll get that on DVD too.