In my last post, I concluded that the NSA's bulk telephony metadata program is a "search" within the meaning of the Fourth Amendment. But because the Fourth Amendment prohibits only unreasonable searches, the next question is whether the program is "unreasonable." This turns out to be a rather complicated question. So, bear with me as I try to work my way through it.
At the outset, it is important to recall exactly what the bulk telephony metadata program does. Under section 215 of the Foreign Intelligence Surveillance Act, as interpreted by the Foreign Intelligence Surveillance Court, the NSA is authorized to obtain from telephone service providers on a daily basis the calling records of millions of Americans. The calling records, or metadata, consist of the phone numbers called by a particular phone number and the phone numbers that have called that particular number. They do not include any information about the identities of the individuals or the contents of the calls. The NSA holds this metadata in a very large database for a period of five years, after which it is expunged.
Whenever NSA analysts have reasonable and articulable suspicion that a particular phone number is associated with a person involved in terrorist activity, they can "query" the database to determine what phone numbers the suspect phone number has been in touch with. This is the only purpose for which the NSA may access the database.
Read more at Huffington Post