We should get a receipt after going through the scanner that verifies where your vote went like you get after pumping gas type receipt. I always get a sinking feeling when that scanner gobbles my ballot.
This is actually prohibited by law, at least in some states.
The reason: the voter cannot be suborned into voting for a candidate, and showing the receipt as proof he did so.
An example: a union member has to show the receipt to the union boss, proving that he voted for the Democrat. I'm sure you can come up with other examples.