"Why are the British government such a bunch of complete arseholes? "
However the cabal of high level data fetishist civil servants (who seem to infect mostly the Home Office) but any of the assorted spy agencies see no reason why it can't (or rather shouldn't) be done.
Inside their heads more is always better. All (recorded all the time forever) is best of all.
Stuff the "safety" BS. This is all about "Give me 6 lines from an honest man and I'll find something with which to hang them."