Is that your answer to how much your privacy is worth?

It's not just that it's a slippery slope or right or wrong. It comes down to efficacy, false positives, false negatives, chilling effects and abuse risks. There's also the risk of incompetence in implementation and maintenance of these systems, not to mention data leak risks. These things should all play into our conversation about how we debate whether this approach is a net positive or net negative on society. Anything less is intellectually lazy.

Ok, do I care that the police could know that I was in town on a particular day when that data is going to be used solely to match against current bolos? Not at all; similar to how I don't care my doctor knows what ailments I have.

In the same way there are risks of incompetence, and data leaks.

False positives and negatives, it strikes me that the risks there are mitigated in the same way as any other single evidentiary point is now, we don't convict people just because they match a description (whether matched by a person or computer in the first instance): that is just an early step in an evidence gathering procedure.

What seems like knee-jerk anti-authoritarian Ludditism in this thread - "they" will use it to lock us all up, we must cripple them technologically - doesn't seem to forward the conversation either, so thanks for responding.