By 2010, GCHQ stated it was logging “30bn metadata records per day. By 2012, collection had increased to 50 billion per day, and work was underway to double capacity to 100 billion.”GCHQ has since “developed new population scale analytics for multi-petabyte cluster,” which allows “population scale target discovery.”In a vision document for 2013, its aim was to have created “the world’s biggest SIGINT engine to run cyber operations and to enable IA, Effects and SIGINT … [as well as] to perform CNE exfiltration, eAD, beaconry, and geo-location.”

Source: Blighty’s GCHQ stashes away 50+ billion records a day on people. Just let that sink in • The Register