I agree with your basic point about the need for balance. Of course there are bad people in the world and of course we need police and courts and the like.
I think the problem today is that many in our current political class don't recognise that need for balance so much as they see "them and us" and even start to forget whose side they are supposed to be on. The truly evil part of the situation is that this result seems almost inevitable. The people calling the shots are exactly the people who necessarily deal with the worst of humanity as part of their job. How could this not affect their perspective? They naturally want to trust their allies, who are the people who would be empowered under all these proposed security measures and aided by restrictions on the privacy and security of others. And of course being influential figures within the government, it is highly unlikely that they will personally ever find themselves on the wrong side of a government screw-up and unable to get the problem fixed very quickly.
I don't think these people are evil. On the contrary, I suspect most people in government, including their agents in the police and security services, are probably just normal people who have a job to do and who genuinely want to do the right thing. As with any large group, there will eventually be a few bad actors included as well and it is necessary to identify and contain them, but that isn't usually the main problem.
However, I do think we're talking about people who are heavily biased, even paranoid, because it would take a superhuman level of detachment not to be when you look at the kind of people they have to deal with at times. I also think in most cases they are ignorant about the technologies they are dealing with, and therefore unable to make rational, objective judgements about the likely effects of the technical measures they propose as policy. Finally, I think that the more senior these figures get within the government and its agencies, the more detached they tend to be from reality for average citizens and the more ignorant or dismissive they can become of how things tend to play out for innocent people in less privileged positions who are nevertheless caught up by the measures the politicians propose.
As the saying goes, power corrupts. It doesn't necessarily have to be malicious or intentional. Obviously in some cases it has been, but often I think the corruption is more of a slow but almost inevitable change in perspective caused by the situations you find yourself in when you have power to wield.
And so it is necessary for those who are looking from outside, those who don't spend disproportionate amounts of their time dealing with a particularly nasty minority of the human race, those who understand the technical issues, to speak out about what is happening and where it could lead. As with any issue of civilised government, in the long run you're going to get much further by educating people about relevant issues and promoting intelligent discourse than you are with wildly exaggerated rhetoric and extreme positions backed by intimidation and ultimately violence. The latter are seductive, and often appear quite effective in the short term, but I doubt they've ever truly solved much.