The National Security Agency's mass tracking and collection of Americans' phone call data violates the constitution, has a chilling effect on first amendment rights and should be halted, accord to a court motion filed by the American Civil Liberties Union on Monday.

In a detailed, legal critique of the NSA programme, the ACLU warned that such long-term surveillance "permits the government to assemble a richly detailed profile of every person living in the United States and to draw a comprehensive map of their associations with one another."