John T, white noise jammers for cell phones are all over the internet , They are however ILLEGAL according to the FCC rules about disrupting communications I forget the section, bad JuJu if you get caught using one. SOme time ago a fellow had one in his car and used it around people on their phones while driving. The problem is the unit he was using was also mucking up the PoPos radar every time he went past them. They pulled him over and I guess it turned to a show,,he was hit with breaking federal laws, as well as disrupting the PoPos radar. Also and I don't remember where but it was up north someplace. A teacher put one in his class to stop the students phones from interrupting his class. One little twit complained to his mama that his phone didnt work in Mr Sonso;s class, yep they found it, and it was not pretty for him.
SO yeah I agree with you,, there are however to many things that can mess that idea up