Can't be. We've had at least 2 guys cite their (shadowy - this is hush hush stuff) credentials in this thread and say it isn't possible. OTOH, if it were possible for some yahoo to do it for a YouTube bite, perhaps some trainable DHS weenies could be found and a defense network established for a few hundred billion $$, so Dave Brown et al of similar paranoid obsession can sleep well........or fixate on something else to make them wake up screaming.

Abel