POWER OF ATTORNEY

     The undersigned, as a Section 16 reporting person of Limelight Networks,
Inc. (the "Company"), hereby constitutes and appoints Jeffrey W. Lunsford,
Matthew Hale, Philip C. Maynard, Yvonne Martinez, Rita Tocco, and Mark L.
Reinstra, the undersigned's true and lawful attorneys-in-fact to:

     1.   complete and execute Forms 3, 4 and 5 and other forms and all
          amendments thereto as such attorneys-in-fact shall in their discretion
          determine to be required or advisable pursuant to Section 16 of the
          Securities Exchange Act of 1934 (as amended) and the rules and
          regulations promulgated thereunder, or any successor laws and
          regulations, as a consequence of the undersigned's ownership,
          acquisition or disposition of securities of the Company; and

     2.   do all acts necessary in order to file such forms with the Securities
          and Exchange Commission, any securities exchange or national
          association, the Company and such other person or agency as the
          attorneys-in-fact shall deem appropriate.

     The undersigned hereby ratifies and confirms all that said
attorneys-in-fact and agent shall do or cause to be done by virtue hereof. The
undersigned acknowledges that the foregoing attorneys-in-fact, in serving in
such capacity at the request of the undersigned, is not assuming, nor is the
Company assuming, any of the undersigned's responsibilities to comply with
Section 16 of the Securities Exchange Act of 1934 (as amended).

     This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4 and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
Company and the foregoing attorneys-in-fact.

     IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 26th day of February, 2008.


                              Signature:  /s/ David M. Hatfield
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                              Print Name: David M. Hatfield
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