I was on shore duty for a spell and, from time to time, I had to travel on the government's business (and on their dime). That almost always involved renting the cheapest econobox that the rental company the government used had on the lot. If my memory is correct, the cars were from National and the cars were Corollas.
On one trip, when I picked up the car, the rental agent gave me a freebie, a little travel alarm clock that was called a "time ball" which was about the size of a golf ball, maybe a little bit larger, with a digital display. It was pretty handy to have on that trip.
After I returned to my duty station, I filed my trip report and my receipts for reimbursement. (They'd give me the airline tickets, but I had to pay for everything else and then file for reimbursement.) A few days later, I got a phone call from the travel department. They wanted to know if I had gotten any freebies from the rental car company. I told them I did. They told me to sent it over, since the government paid for the car, the clock belonged to the government.
I could see the logic of that. What I could also see was that the clock would be taken by one of the weenies in the travel department.
I took an interoffice envelope home with me. When I got home, I picked up the clock and I realized that, because of its round shape, it wouldn't fit very well in the envelope. So I put the clock in the envelope, put the envelope between two boards, and applied some percussive adjustment. It fit a lot better. The next morning, I dropped it into the interoffice mail.
The next day I got another call from from the travel department. They wanted to know what happened to the clock. I asked what was wrong with it. They said it was smashed to bits. I said: "I don't know what to tell you, it was fine when I put it in the envelope."
After that, I refused all of the freebies.