WASHINGTON (TIP)The National Security Agency programmes that collect huge volumes of Internet data within the United States pass are constitutional and employ “reasonable” safeguards designed to protect the rights of Americans, an independent privacy and civil liberties board has found.

In a report released on Tuesday night, the bipartisan, five-member Privacy and Civil Liberties Oversight Board, appointed by President Barack Obama, largely endorsed a set of NSA surveillance programmes that have provoked worldwide controversy since they were disclosed last year by former NSA systems administrator Edward Snowden.

Under a provision known as Section 702, added in 2008 to the Foreign Intelligence Surveillance Act of 1978, the NSA uses court orders and taps on fibre optic lines to target the data of foreigners living abroad when their emails, web chats, text messages and other communications traverse the US.

Section 702 includes the so-called PRISM programme, under which the NSA collects foreign intelligence from Google, Facebook, Microsoft, Apple and nearly every other major US technology firm. Because worldwide Internet communications are intermingled on fibre optic lines and in the cloud, the collection inevitably sweeps in the communications of Americans with no connection to terrorism or foreign intelligence.

Since the Snowden disclosures, activists have expressed concern that a secret intelligence agency is obtaining private American communications without individual warrants. Some have questioned how such a programme could be legal under the Constitution.

The board, including a Democratic federal judge, two privacy experts and two former Republican justice department officials, found that the NSA monitoring was legal and reasonable and that the NSA and other agencies take steps to prevent misuse of Americans’ data.