Not sure how you would go about ensuring that the device was being used by the individual, unless you worked it based on a biometric key, but biometrics has its own problems and vulnerabilities. You'd also have to figure out how to ensure the device itself was not compromised by spyware/malware. You'd have to purge the rolls regularly (although that should be pretty easy to do electronically, I'd think).

I dunno, I'm open to the idea, but there'd have to be a plethora of precautions and some kind of traceable "paper" trail and there's a slew of vulnerabilities that I'm not convinced we could easily solve.