S.C. Code Ann. § 17-29-20: Installation of pen register or trap and trace device prohibited.

(A) Except as provided in this section, no person may install or use a pen register or a trap and trace device without first obtaining a court order under Section 17-29-40.

(B) The prohibition of subsection (A) does not apply with respect to the use of a pen register or a trap and trace device by a provider of electronic or wire communication service:

(1) relating to the operation, maintenance, and testing of a wire or electronic communication service or to the protection of the rights or property of the provider, or to the protection of users of that service from abuse of service or unlawful use of service; or

(2) to record the fact that a wire or electronic communication was initiated or completed in order to protect the provider, another provider furnishing service toward the completion of the wire communication, or a user of that service, from fraudulent, unlawful, or abusive use of service; or

(3) where the consent of the user of that service has been obtained.

(C) Any person violating the provisions of subsection (A) of this section is guilty of a misdemeanor and upon conviction must be punished by a fine of not more than one thousand dollars or by imprisonment for a term of not more than one year, or both.