New leaked files reveal more about NSA satellite eavesdropping

Newly published documents from Edward Snowden have shed more light on American surveillance operations in the UK. The Intercept details how the NSA and GCHQ used information gathered by Menwith Hill Station, a massive but tightly sealed facility that intercepts satellite data transmissions worldwide. Among other things, the files appear to include evidence that links UK-based surveillance to American anti-terrorism campaigns outside official combat zones.

While many surveillance efforts focus on the internet’s connective "backbone" cables, Menwith Hill intercepts wireless signals, using an array of antennae and US government satellites to capture up to 335 million pieces of metadata in a 12-hour period. Previous reports — including an earlier Snowden leak — have already revealed some of its capabilities. But The Intercept includes more details, particularly about the UK’s involvement in "capture-kill" operations against suspected terrorists. It describes how the GHOSTHUNTER program traced the location of targets "when they log onto the internet," often in internet cafes. A different program called GHOSTWOLF, which let the NSA and GCHQ monitor traffic from Yemeni internet cafes, is part of a plan to "capture or eliminate key nodes in terrorist networks" by tracking their locations.