The nominee to head the US National Security Agency (NSA) has defended bulk data collection but also wants more transparency about the service.
Vice-Admiral Michael Rogers (pictured) told a Senate confirmation hearing on Tuesday that the NSA needed to be able to access vast amounts of data to thwart terror attacks.
Rogers said he saw a need to maintain the law authorising bulk collection of phone records, a practice attacked for trampling on the rights of ordinary people.
"The telephone metadata programme ... was designed to map the communications of terrorists so we can see who they may be in contact with as quickly as possible," he said. "I believe we need to maintain an ability to make queries of phone records in a way that is agile and provides results in a timely fashion. Being able to quickly review phone connections associated with terrorists to assess whether a network exists is critical."
But Rogers said he believed the public had a right to have better information in view of the revelations leaked by former NSA contractor Edward Snowden.