Is there a case documented in U.S. History where an employer obtained "legal" rights to "investigative services" of a temp employee? Secondly, is there any case documented where there has been anyone that voluntarily surrendered their constitional rights? Let me know your thoughts.

Your posts makes almost no sense, can you explain in detail what you are asking.

Almost any employee signs on the application that the employer may conduct a background investigation. This is normally not limited and can be criminal, past work history, credit history and more.

Constitutional rights can be taken away, ( happens to felons all the time, right to vote, right to carry a firearm, right of freedom)