>since you don't know people's secrets, how can you possibly make that determination? //

It's a conversation. You can tell me everyone you know has secretly murdered at least one person and progress things somewhat (I'm being flippant, of course).

Saying things in public is not "being on record" though. Someone has to make the effort to look up about you, and we all wore a stupid costume, got drunk and made a pass at someone, dropped some litter, swore, or whatever ... in a Western Democracy are you going to shame me for normal behaviours, I think you'll struggle.

>Can you really not imagine how even the most innocent of statements or criticisms can be construed by a paranoid power in the worst possible light? //

Yes, what's the motivation? Fascist takeover? We're all in the same boat aren't we: OMG my neighbor looked at porn, let's burn him at the stake??

Sorry, I'm not interested in you making a determination that the private lives and conversations of others are similar to yours, nor do I accept any premise that simply because you've judged people to 'not be terrorists' and the risk of governmental abuse to be low, that there is no real risk of agencies abusing such data. Your justifications are personal, and frankly, should have no bearing on other people's lives. If you can't imagine real cases of private conversation (or DNS lookups, or whatever) being used to profile and target particular groups for fairly undemocratic reasons, then that's a failure of your imagination. We are not all in the same boat, especially if by 'boat' you mean we all socialise with the same people, have the same political beliefs and actions, or even share our sexual orientation.