I've always worked on the assumption that it is within my right to build my private facility out of copper if I choose, and the fact that your cell phone doesn't work in my facility is your problem not mine. I am not "jamming" any signals. I would be interested to hear counter-arguments from those familiar with the FCC rules on this matter.
Maybe if intent to jam wireless could be demonstrated, but there are no codes I know of that require a certain level of permittivity in a building, and indeed many buildings all but squash signals- and that is the user's problem.
