Earlier quoted context omitted.
I don't see why it's like that at all. Am I not allowed to create a small faraday cage in my garage, and inside that test out a cell phone jamming device? Why does it matter if there's literally no measurable effect on the surrounding property?
I'm not a lawyer but I do read FCC regs for fun... A passive faraday cage on your own property that's not open to the public probably isn't an issue. As far as size goes you would be subject to local building codes of course. Once you get into active jamming however that requires you to transmit and to transmit you need a license from the FCC. The right to transmit anywhere in the US is under the FCC's jurisdiction a…
It seems very much different to me, because all of those things have very obvious externalities for your neighbors. My example, where you build a faraday cage and test a signal jammer inside that cage, has no externalities (assuming a hypothetical perfect faraday cage). There would be no measurable signal an inch outside the faraday cage, and certainly none at your neighbor's property.