You are now definately in the tin-foil hat brigade. I'm sure the nay-sayers will be impressed. Whether you (or, more importantly, they) like it or not, there is guilt by association.
It has been explained to you that because something is merely possible, does not make it likely/plausable/VALID or any other word giving weight or credence to your scenario. In fact, your statement is utterly incorrect, as several posts on this very thread point out why your opposition to GPS reliance isn't valid. Get that; OPPOSITION TO GPS RELIANCE. That is the key- not whether it is possible for terrorists to build weapons that utilise GPS. You have been rebutted most conclusively, and your seeming inability to grasp that is what is relegating you to the lunatic fringe.
If you are so sold on your conviction, I put it to you that it is up to you to take apart each and every rebuttle post on this thread, and sway the wider audience. Because just sitting back and declaring that no-one has rebutted YOU, and that your scenario is possible, and therefore a show-stopper, just isnt flying.
While your posts may be a fine example of circular argument, persuasive they are not.