Trucking: Motor Carrier operating under Contract Carrier but Operating Without Contracts, contract carrier, legal answer

Question
Hello, I was wondering what the punishment was, if any, for a "Contract" carrier (as listed in the FMCSA), who is not doing any contracts with clients and not insuring their cargo in case of accidents?

Answer
Miluska, there is probably a correct legal answer to this but from a practical point of view if no one complains probably no consequences.  To my knowledge the FMCSA is not interested in this issue.  Regulations used to require contracts to be written but I'm not sure anymore.  Even if a verbal contract is permissible it's a bad business practice.  Any reputavble carrier and shipper will require a written contract to avoid problems down the road.
Jim.