[Rebelbase]

"Sound based. It would triangulate on the initial bang. "

It seems like it would be easy to fool the system with decoy gunshots.

[LibWhacker]

Yep. Nothing's foolproof. There must be a way to defeat it. But I wouldn't want to be part of the group of Stupidstinians that tries to do it in combat. :-(

Wish I could find a reference to the show on discovery.com. They seem to have taken it down. I'm sure someone else will remember the show. It was amazing . . . Every bullet's path traced out in a different color as the machine gun was being fired. My impression was that soldiers in the field would someday be able to wear these things on their helmets, kind of a heads-up display showing where enemy fire was coming from.