In order to protect copyright IP, clients should require that their vendors sign contracts stipulating that all of the vendor's work product will be owned by the client. If a vendor who is not an employee of the client creates work product on the job, then the vendor will own that work product unless the vendor signs a contract saying otherwise. Specifically, these vendor contracts need to contain a "work made for hire" provision that grants all copyright IP to the client and deprives the vendor of any claim to ownership of that IP.