"650 volts" is a typo, right? That wouldn't even arc through the air, never-mind someone's skin. Hopefully that company has good lawyers, because the first person to attempt using one of these is going to get their phone stolen, and the crap beat out of them.
Edit- Yep, it is a typo, their site (http://www.yellowjacketcase.com/
) says 650,000 volts. That makes more sense.