18 U.S.C. § 2706 : US Code - Section 2706: Cost reimbursement

      (a) Payment. - Except as otherwise provided in subsection (c), a
    governmental entity obtaining the contents of communications,
    records, or other information under section 2702, 2703, or 2704 of
    this title shall pay to the person or entity assembling or
    providing such information a fee for reimbursement for such costs
    as are reasonably necessary and which have been directly incurred
    in searching for, assembling, reproducing, or otherwise providing
    such information. Such reimbursable costs shall include any costs
    due to necessary disruption of normal operations of any electronic
    communication service or remote computing service in which such
    information may be stored.
      (b) Amount. - The amount of the fee provided by subsection (a)
    shall be as mutually agreed by the governmental entity and the
    person or entity providing the information, or, in the absence of
    agreement, shall be as determined by the court which issued the
    order for production of such information (or the court before which
    a criminal prosecution relating to such information would be
    brought, if no court order was issued for production of the
    information).
      (c) Exception. - The requirement of subsection (a) of this
    section does not apply with respect to records or other information
    maintained by a communications common carrier that relate to
    telephone toll records and telephone listings obtained under
    section 2703 of this title. The court may, however, order a payment
    as described in subsection (a) if the court determines the
    information required is unusually voluminous in nature or otherwise
    caused an undue burden on the provider.