If they did have that capability do you think they would use it to take down and prosecute a small time drug dealer exposing what they are doing? Even exposing this capability to the Police by give them “secret” intelligence would inevitably result in the knowledge of their capabilities leaking.
If they do have this capability it is only every going to be used for large scale organised crime, terrorism and state security.
They do have this capacity. Given that the existence of this capacity is now public, it is my belief the UK is mainly limited by a combination of selective enforcement, lack of courts and lack of police (weirdly, given their preferred “tough on crime” rhetoric, U.K. courts and police are severely underfunded right now).
They might like the cost savings for evidence gathering, but there’s something ridiculous like a half million backlog of court cases in the U.K. right now so the rest of the justice system isn’t in a position to use that evidence.
Well, I don't know about phone conversations, but every Tom, Dick and Harry gets access to web surfing history. Given that highly casual attitude - formalised into law! - I wouldn't put it past them to informally do whatever they like with the rest of it.
If they do have this capability it is only every going to be used for large scale organised crime, terrorism and state security.