Re: I Remember the Early Days of Menwith Hill
the old COMINT system was UKUSA (1947 agreements online somewhere) which morphed into 'keyword-driven' ECHELON "E" based at Menwith since 1954 compulsory purchased farms (according to open published parliamentary reports) with five-eyes running it, UK, CAN, NZ, AUS as 'junior' partners
later "E" went for global take 99.9999% of world telecom traffic, from around 1966 when focus was taken from just the Soviet threat...France later was a bit miffed about economic atacks of this spookery (Thomson-CSF/Brazil deal that was undercut, Airbus etc) , also Germany (see Enercon/Kenetech wind-turbine design as examples that might well be "E") ...
...which hence morphed into the current tiered-partner agreements with (matrix of many many partners) getting more or less of the full-take (according to Snowden's docus) depending on reciprocal sharing etc etc
The whole BT network was admitted in court in the 1970's to be plumbed directly into & through the National Security Agency Field Station F-83 , though the BT engineer said he'd introduced the maps by mistake, and could he have them back please!
The BT YHTS Hunter’s Stones in Stainburn forest is absurdly used by internetters as a geocache location, whilst the next hop along YTIL Tinshill, North Leeds, looks very crumbly as the atomic blast resistant concrete tower is succumbing now to decades of Yorkshire rain.
(Duncan Cambell has written well about this overtake, over collect, over the years. However, I'm sure it is all legal nowadays, and sovereign governments can do whatever they like)