The physical object is not what matters. Same thing that prevents someone from stealing a license plate or counterfeiting one or putting a bogus health inspection cert in their restaurant window. Obviously if you were to affix a medallion (or license) to a vehicle at some point that would be discovered and you would be in hot water. Obviously.
You are not buying the medallion. You are buying the right to operate a taxi. The medallion is just an easy way for a) riders and b) enforcement to at least attempt to judge who is legit and who isn't.
And as the financial people noted they can remove the medallion if someone is in default. If all you had was a number painted on the side of a taxi that wouldn't work the same (someone could say "oops" and still pickup fares.)
You are not buying the medallion. You are buying the right to operate a taxi. The medallion is just an easy way for a) riders and b) enforcement to at least attempt to judge who is legit and who isn't.
And as the financial people noted they can remove the medallion if someone is in default. If all you had was a number painted on the side of a taxi that wouldn't work the same (someone could say "oops" and still pickup fares.)