>>Once criminals recognize the device they will either steal them or smash you in the face to destroy the evidence Such a system for security ought to have vid

>>Once criminals recognize the device they will either steal them or smash you in the face to destroy the evidence Such a system for security ought to have video storage inside a hard shell with a high speed 4G link, able to send the last minute of video/sound (with gps position) to the police at the push of a button. The high speed link is probably a bit bulky (batteries) and will probably always be put into a pocket or something anyway, even without security considerations. But sure, criminals could get some equipment to disturb mobile connections.