From Bruce Schneier’s “News” (Crypto-Gram: 15 September 2007):
Taser — yep, that’s the company’s name as well as the product’s name — is now selling a personal-use version of their product. It’s called the Taser C2, and it has an interesting embedded identification technology. Whenever the weapon is fired, it also sprays some serial-number bar-coded confetti, so a firing can be traced to a weapon and — presumably — the owner.
http://www.taser.com/products/consumers/Pages/C2.aspx