I can let anyone with a valid license drive my car on a public road and anyone drive it on private property. Any quantity I choose, it's my car.
If they issue a ticket without verification of the driver then there is no way that they can prove who was driving. Without a witness and/or verification there is no way that someone could defend themselves against the accusattion. In America you have the right to due process. Speed cameras don't allow for due process and that's why they aren't moving violations and why the municipalities who issue them know they aren't really enforcable..
Most people just pay or don't go through the trouble of fighting it if it goes to collections. They know this.
@Cyclonepride It's a total scam under the guise of safety.