[lurker456]

That's not proof it doesn't work. If you ran the GCHQ and you had a way to track everyone, would you let it be used to solve petty crime ? Much safer to use it sparingly.

[secfirstmd]

The Security Service has access to all publically paid for CCTV cameras in the UK. Motorways, airports, city centres etc

[achamayou]

Would you not? It would make you pretty popular for one thing, and much easier to get funding next year.