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Communications of the ACM


Having a Conversation About Bulk Surveillance

rally against mass surveillance

Protesters at a rally against mass surveillance in Washington, D.C.

Credit: Rena Schild /

Bulk collection of signals intelligence (bulk surveillance, for short) is a controversial topic. The most well known program to collect signals intelligence "in bulk" is the bulk collection of telephone metadata authorized by the Foreign Intelligence Surveillance Court under Section 215 of the Patriot Act. Opponents of the program contended the program is an unwarranted invasion of privacy, a general search of exactly the kind prohibited by the 4th Amendment to the U.S. Constitution. Supporters of the program asserted it was and is a critical tool in the nation's counterterrorist arsenal.

On May 8, 2015, the U.S. Court of Appeals for the Second Circuit held the language of this section could not plausibly be interpreted as authorizing bulk surveillance, though it did not rule on whether the program would be constitutional even with statutory justification. On June 1, Section 215 authority for this program expired, and on June 2, a new program was enacted into law under the USA Freedom Act requiring the metadata be held by phone companies. The National Security Agency lost the ability to query this metadata broadly based on prior arrangements from the Foreign Intelligence Surveillance Court, but continued to have access to specific numbers with an appropriate order issued by the Court.


Howard Golden

Dr. Lin muddies the water with a discussion of what "bulk" means. As a practical matter, it is far easier to define "bulk" as any collection not authorized by a court under the provisions of the Fourth Amendment to the U.S. Constitution, based on a showing of "probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized." As far as "collection," it means any attempt to receive, perceive, inspect or record data where the parties have a reasonable expectation of privacy. These definitions do not exclude data collected by third parties.

It is insufficient to claim or prove that a program is helpful without first establishing that it is Constitutional. In the absence of a Constitutional purpose and process no government action is permissible. Rather than attempting to circumvent the clear language and intent of the Constitution, the advocates of bulk collection should seek and obtain the necessary Amendment to make their activities Constitutional.

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