The lawyers of course. This is America after all.

The problem with opt-out is that you confirm that a real person is reading the spam. You might not get messages from that exact source again, but you may well get on even more spam lists.

All this confusion over IP terminology...

Recipes can be copyrighted (the prose/description at least, not merely the ingredient list). To claim the kind of rights they're talking about here would require a patent. Of course, qualifying as novel and non-obvious would be difficult.

How long before they start going after Google for linking to 'blaspheming' sites.

I note that Wolfram|Alpha happily deep-links to Google Maps.