However, after giving it more than a seconds thought, I realised most of my life I've had no reason to pursue a second language so I am limited to the anglosphere. In addition, 5 of the 6 anglosphere countries form the Five Eyes alliance, so my data would probably go back to the UK government no matter what.
Not speaking the local language would lock you out of certain types of jobs with language requirements, e.g. civil service jobs and customer facing roles typically, but depending on what you want to do they might not care at all.
But yes, leaving the UK to escape spying elsewhere in Europe wouldn't really achieve much.
If you have the right to live & work in the EU, you're very lucky & years ahead of some of us. I've been learning German for 5 years & spent a lot of time looking into the EU Blue Card program.
This might not apply to UK citizens very much longer if the referendum vote goes the wrong way.
Everyone got English :)
It's the same here in Norway, we have multiple English speakers at work, and the working language is English in a lot of places.