[Bartweiss]

This is the strongest point. Not having anything you're ashamed of does not mean not having anything to hide - it's all too possible for completely harmless traits like ethnicity and sexuality to become targets for someone else.

[nkrisc]

Your actions may be legal now, but that may not always be the case. You may be protected from retroactive prosecution now, but that may not always be the case. Data doesn't just go away.

[pessimizer]

The most scary aspect is that if I know everything about you, I can frame you for a crime for which you will have no alibi, or threaten to in exchange for you doing what I ask.

The second was a tactic often used by the Stasi to create more operatives - call someone in for questioning, accuse them of a crime for which they have no alibi, such as spying, and when they protest their innocence, ask them to help the government with something to show their good faith. That something could easily be to provide a pretext for arresting the real target.

[DanielBMarkham]

The Stasi is a good model for how quickly and badly this can go off the rails.

The way it's supposed to work is that you have some public event of importance: a crime, a person applies for a security clearance, or whatnot. Based on that event, the state then conducts and investigation to see if there are any data they can discover that might lead to a response.

The new way of working is that you collect all the data, on everyone, all the time. Then there's no more event. The only thing you do is pick out the person. Once you have the person, it's a simple data mining exercise (along with a lot of interrogation techniques) that takes care of the person. What's the old saying in communist countries? "You have a man. You have a problem. No more man, no more problem"

Functional societies focus on events. Dysfunctional societies focus on the people.