Postal Service Practices

Your local post office will not accept your credit card when you swipe it for purchases unless it is signed. My credit card says "see ID" on the signature line. They rejected my card for that reason and said the Postmaster General requires a signature. Think about this, my card requires seeing ID, the Postmaster's ruling requires no ID and you could pick a card up from the street, swipe it at the post office and walk away committing fraud.
I've used this practice for years and retailers "love it".
What is wrong with our Postmaster general??? 
Perhaps this practice is evident of other reasons the postal service is losing huge sums of money. Poor decision making at the Top!