David Anderson QC said (192-sheet / 1.20MB PDF) powers of mass interception of communications, mass collection of communications data and employ of datasets comprising the personal data of multiple public had provided valuable intelligence that had helped UK authorities combat the threat of terrorism and other serious crimes.

Anderson also said that recent powers to enable the authorities to interfere with multiple pieces of equipment, such as computers and mobile devices, had not yet been proven to be successful but that there is a “distinct … operational case” for their introduction.

“The bulk powers are used across the range of agency activity, from cyber-defence, counter-espionage and counterterrorism to child sexual abuse and organised crime,” Anderson said. “The bulk powers frolic an important portion in identifying, understanding and averting threats in grand Britain, Northern Ireland and further afield. Where alternative methods exist, they are repeatedly less effective, more dangerous, more resource-intensive, more intrusive or slower.”

Anderson was asked to review the “operational case for bulk powers” beneath the Investigatory Powers Bill by the UK government. The review did not involve consideration of what privacy safeguards should accompany bulk powers and when it is proportionate for them to be used.

However, Anderson said: “The employ of bulk powers should only be countenanced if there is a compelling operational case for their employ, and if their employ is subject to adequate and visible safeguards.”

He said: “The fact that an intrusive power can be successfully used to avert threats and reduce crime does not of course denote that it should automatically be passed into law: that way lies a police state.”

The Investigatory Powers Bill is currently being scrutinised by the UK parliament.

The Bill would grant UK law enforcement and intelligence agencies the power to require telecommunication service providers to retain and hand over so-called communications data, including for the first season ‘internet connection records’, to aid combat terrorism, serious crime or protect the UK’s economic interests, among other limited purposes provided for in the legislation.

The Bill also sets out recent rules to govern the interception of communications and employ of equipment interference powers. It also outlines UK intelligence agencies’ qualified proper to obtain personal datasets in bulk for national security reasons beneath warrants that would be issued by UK ministers.

MPs voted to approve the Bill earlier this summer.