I think it's worth reminding everyone that the UK is far from the only country in Europe to be doing this:
(New users can only post two links, so I can't post the reports I'd like. Instead, have a look at that Wiki article and follow citations 10-15).
Those are all Snowden leaks, detailing how Germany, France, Sweden, Denmark, Norway, Spain, Italy, Switzerland and the Netherlands are all either voluntarily sharing mass surveillance data with GCHQ and the NSA, running their own such operations, or a combination of the two. I think that there are very few countries with the technological and economic capacity for mass surveillance that are not attempting it (Czech Republic, a number of Eastern European countries with memories longer than a decade). It was, after all, the EU which passed this directive in the first place.