I constantly bring up the EM spectrum in discussions of IP, and for good reason. It's quite difficult to justify rights in one but not the other, leading some people to unpalatable conclusions. Heck, even Stephan Kinsella, the big anti-IP poomba, isn't sure whether there should be rights to radio waves.
But recently, I've found yet another parallel. Consider the case of someone who, like in lots of instructive thought experiments, wants to block the propagation of radio waves from a nearby tower so that people can't receive them (well, extract information from them, but you get the point).
There's a device that lets you block EM waves, known as a Faraday cage. I didn't know how they work before, but it turns out that, by being made of conducting material, their electrons realign so as to produce the *opposite* field from the one around it (which superposes over it and cancels it out).
See where this is going? To protect your right to to transmit information via EM waves, you need to be able to prevent others from ... er ... instantiating the same pattern! Now, where else have people asserted that kind of right?
(By the way, first post ever from my first smartphone, the wonderful Samsung Moment. And no, unlike when Tyler Cowen promotes a product, I didn't get it for free or otherwise get paid to say that. No, the links weren't added from the Moment.)