https://www.techdirt.com/articles/20180725/20114640312/uk-tribunal-says-gchq-engaged-illegal-telco-collection-program-more-than-decade.shtml

UK's NSA -- GCHQ -- has lost legal battle after legal battle in recent years, most of those triggered by the Snowden leaks. The UK Appeals Court ruled its bulk collection of internet communications metadata illegal earlier this year. This followed a 2015 loss in lawsuit filed over the interception of privileged communications, resulting in a destruction order targeting everything collected by GCHQ that fell under that heading.

Some battles are still ongoing, with several of them spearheaded by Privacy International. PI's work -- and multiple lawsuits -- have led to the exposure of GCHQ's oversight as completely toothless and a declaration that the agency's surveillance agreement with the NSA was illegal… at least up to 2014's codification of illegal spy practices. (This codification was ultimately ruled illegal earlier this year.)