Re: Gosh, a voice of reason speaking to our government!
To be perfectly honest, I don't think the spooks themselves want this mass surveillance either. From their perspective, this is also a lose-lose prospect.
Look at this from the spooks' point of view for a while. They get their mass surveillance law, and within days they get the power and ability to round up trolls, loud-mouthed blowhards, keyboard warriors and assorted noisy plonkers by the dozen (and one look at any unmoderated forum will show up these sorts of people by the thousand). The problem here is that loud trolling isn't actually much of a crime, save against the rules of grammar and politeness. People are rarely physically harmed by words on an internet forum.
Even deluded Walter Mitty types rarely do all that much harm. The likes of the Baron of Castleshortt are harmless nitwits, who provide military forums with much amusement debunking their exaggerated claims, but who are not actually anyone's problem.
Actual terrorists, on the other hand, tend not to make a great deal of noise. They especially won't make much noise after Mr Rehman and his wife both got life sentences for terrorism-related offences, having shot their mouths off on Twitter.
No, what is a lot more likely to happen is that the security services will get swamped with data, fail to spot several serious plots which either go to fruition or are picked up on by the police and stopped, and then the heads of the security services will be forced to resign for incompetence. A few times round the block on that one, and the security services will end up with mass surveillance data that they either don't use, or pay only the most cursory attention to unless a target is clear. In other words, the government legislates to piss a huge amount of money up the wall before tacitly admitting that it was all a waste of time and the old tried & trusted security methods were a lot more useful.