Federal law requires the Administrative Office of the U.S. Courts to http://www.uscourts.gov/library/wiretap.html">report each year on law enforcement wiretapping activities which gives the public a sense of how often the government intercepts phone calls emails and other communications. Unfortunately there's no similar public reporting for the government's use of pen registers and trap and trace devices which record "routing" information rather than contents of communications. EFF has submitted several FOIA requests to try to document the frequency of this electronic surveillance in recent years.
FOIA Releases - FBI
June 8, 2010
FBI's June 8th release of documents related to EFF's FOIA request.
June 8, 2010
FBI's release letter for documents related to EFF's FOIA request.
FOIA Releases - Department of Justice
September 9, 2009
Letter from Assistant Attorney General Daniel J. Bryant to Senator Patrick Leahy dated 11/29/01 enclosing Attorney General's Responses to Questions Submitted by Senate Judiciary Committee Chairman Patrick Leahy on November 1, 2001.
March 19, 2009
Release letter and memo from Department of Justice, Office of Information Policy regarding use of pen registers to obtain URLs.
February 1, 2009