Okay, here's another argument. If property owners have the absolute right to mess with the signals that come on their property, does that mean that it should be legal to pirate satellite TV service?
Your question is hard to answer without first addressing the hidden assumptions. Suppose as the initial point of departure that I decide to print a newsletter, and slip it into everyone's mailbox, but stamp the envelope with a disclaimer stating that you may not read it unless you pay me $50 per month. What would the legal status of that be? The marking on the envelope would be interpreted as a contract of adhesion, and courts would not support my right to demand $50 from individuals caught reading the newsletter. In this case, the courts would be deciding the matter correctly.
Suppose, though, that I decide to get those dirty freeloaders by encyphering my newsletter with a new alphabetic cipher each month, and then selling the key for $50 per shot. This might be a sensible approach; it limits freeloaders and improves my revenue. It raises a question, though: what if some people enjoy such puzzles, and decide to try and break the cipher each month? Since I've chosen to use alphabetic ciphers, it happens that any reasonably interested person could in fact crack the cipher without much trouble. Can I then sue those persons for $50? The answer is again no, for the same reason as above. A contract of adhesion forbidding them to crack my cipher will not be upheld in court.
Suppose finally that these enterprising folks decide to sell my monthly key for $30, thus undercutting my price. This is a trickier question, but the ultimate answer is that they may not do this. If I construct the case correctly, I can demonstrate that this is a copyright violation on par with re-selling my newsletter, which you are not permitted to do even after I give you a free copy.
What this should make clear is that RF is in practice no different. If I beam RF energy into your house, you can make any use of that energy you deem fit. You can use it to induce electricity in an antenna to run a micro-powered device. If it's in the clear, you can play it through your radio or TV. If it's encrypted, you can play it as white noise. If you have the know-how, you can decrypt and watch it. What you may not do is, for example, sell cracking boxes for others to listen to my broadcast.
BTW, this applies to cell phone conversations as well. A law stating that you may not listen to RF signals beamed through your home is not valid. The onus is on the provider to ensure privacy by whatever means are at their disposal. Since unbreakable crypto exists today, there's no earthly reason that privacy can't be ensured.