I agree. I think that US law is actively harmful in this regard. It should be possible to be in public spaces without having to worry about being recorded, either by authorities or other people.

This reverses the subject, though: even if we grant that private civilians should have a (possibly limited) expectation of privacy in public, civilians acting in a public capacity, like the police, should not. Given the enormous power they have to act outside the law with impunity, removing the only check on that power— transparency into their conduct— would be a mistake. One only need to consider any of the many times police have been caught outright lying by video surfacing afterward to understand why.

I agree entirely. We give police extraordinary power over us, and it seems completely reasonable that they have little expectation of privacy when using those powers.