1. Cards are issued based on locality.
2. Cards are signed by the issuing officer.
3. Cards are meant to be used in a local community, where the ticketing officer recognizes the signee.
Source: Had my share of these cards. (Never used one)
Source: Had my share of these cards. (Never used one)
2. How much validation of signature is there? Do other police officers memorize each others signatures? That seems unlikely
3. I'm sure it'd be pretty easy to get a list of a large number of police officers for any given locality.