They probably are, so the NSA can request such data from them if they need it. https://www.theguardian.com/uk-news/2013/aug/01/nsa-paid-gchq-spying-edward-snow

They probably are, so the NSA can request such data from them if they need it. https://www.theguardian.com/uk-news/2013/aug/01/nsa-paid-gchq-spying-edward-snowden https://www.theguardian.com/uk-news/2013/aug/01/nsa-paid-gch... https://www.theguardian.com/uk/2013/jun/21/gchq-cables-secret-world-communications-nsa https://www.theguardian.com/uk/2013/jun/21/gchq-cables-secre... And so on.