In one of the "John Doe" cases targeting Boston University, consolidated under the heading London-Sire Records v. Does 1-4, after the university advised the Court that it could not identify John Does #8, 9, and 14 to a reasonable degree of technical certainty, Judge Nancy Gertner deemed the letter a motion to quash, and granted it, quashing the subpoena as to those defendants:
The Court treats Boston University’s 9/23/08 Letter as a Motion to Quash and GRANTS the motion with respect to Doe Defendants # 8, 9, and 14. The University has adequately demonstrated that it is not able to identify the alleged infringers with a reasonable degree of technical certainty. As a result, the Court finds that compliance with the subpoena as to the IP addresses represented by these Defendants would expose innocent parties to intrusive discovery. Accordingly, under the test laid out in its 3/31/08 Order, the Court declines to authorize discovery and quashes the subpoena as to Does # 8, 9, and 14.
Source: Recording Industry vs. The People
http://recordingindustryvspeople.blogspot.com/2008/11/judge-quashes-boston-university.html