This is an important point. Most people are deciding what they're ok with based on today's circumstances, government etc. What happens if some years from now, your past behavior is at odds with the current government. You will be flagged and there will undoubtedly be consequences, which, even if minor are still negative. E.g., flagged for searches at border crossings.
It's interesting that people worry about "the basilisk" and all of this happening with AI, but not about the fact that future governments and revolutionaries are equally likely to look back on old data and judge you for it - and have a much greater capability to use that data to do you harm.
It can be much worse than what you mentioned. At some point this surveillance technology will trickle into the hands of every government and they will take advantage of it. What's the chance that none of the warlords in countries in conflict will use this for their advantage? And that could easily be used for mass murder.
This is an important point. Most people are deciding what they're ok with based on today's circumstances, government etc. What happens if some years from now, your past behavior is at odds with the current government. You will be flagged and there will undoubtedly be consequences, which, even if minor are still negative. E.g., flagged for searches at border crossings.