Google discloses IP address of user making threats to congressman

This is from the affidavit:

6. On March 27, 2010, an Emergency Disclosure Request was completed and faxed to Google Inc, the owner of YouTube. The request was for Google to provide the IP address(es) used by the user who posted the YouTube video described in paragraph 5, above. Google provided the IP address - 74.109.58.150 - that was used at various times by the user between March 24, 2010 4:48 p.m. PT and March 26, 2010 04:58 a.m. PT.

7. Subsequently, the IP address 74.109.58.150 was subsequently provided to Verizon Internet Services. Upon being served with an "Emergency Situation Disclosure Request By Law Enforcement" form, Verizon provided the subscriber information for the user assigned IP address 74.109.58.150 between March 24, 2010, 4:48 p.m. PT, and March 26, 2010, 04:58 a.m. PT. According to Verizon's records, the subscriber to the IP address, at the specified time was: John Hopkins, 1653 Benner Street, Philadelphia, PA 19149.

What I'm curious to find out is if an Emergency Disclosure Request is legally compelling.