As for having to reveal/prove my identity to the police: I could do without that, but I consider it mostly a non-issue. In practice it happens rarely, and if it does the police officers tend to be pretty friendly and reasonable. Case in point, one of the two or three times this has happend to me in my life, my ID was invalid as it had expired several months before. They were basically like "Well you better get a new one soon, m'kay?" and then sent me on my way. YMMV of course.
The big difference though between the ID card thing and privacy violations by spying is that the spying happens behind people's backs, and they may never know how broadly their rights are violated until one day the gathered information is used against them. There can be no effective oversight and that's why it must not be allowed to happen in the first place.
If on the other hand the police started abusing their authority – acting like dicks, grabbing people en masse to check their IDs on every street corner, it would be immediately obvious to everyone and could presumably be corrected (by vote, protest, civil disobedience, etc).