Re: What was the question?
But in the UK it's not possible to say "this law is only for .... " since once a power has been bestowed, it is generally used for whatever the authorities deem necessary or desirable, rather than within the strict boundaries it was originally intended.
Actually, it is possible for the government to say, in the wording of the law, that it is only for use in specific cases X Y and Z, put in sufficient judicial oversight to ensure this remains the case, and punish those who abuse the powers.
The problem is the laws are never written that way. We get spun the line of "we will only use this to catch terrorists/paedophiles", without any legal backing to control it's use. Then function creep comes in, and we are stomped into the ground, often with a "why are you complaining, we are catching criminals, if you have nothing to hide..." yada yada yada.
In addition to this, most people just don't care. I know here, on a tech site, we think about these things, but the man on the street will often just say "They are doing it for our own good". It is certainly not high on their "reason to vote" list. They would rather listen to knobs telling them that all the worlds ills are caused by Europe, or work-shy scroungers, or bankers, or whatever other group is being scapegoated today to distract us from what is really going on.
As pointed out in a famous poem, they will not speak out until the government come for them, and by then there will be noone left to speak out for them.