> It's a long-standing principle that you have no expectation of privacy in public spaces.

There are limits to what we consider acceptable even in public spaces; for example, upskirt photos aren't ok even you're in a public place. I think it's still reasonable to consider that one day (maybe today, for many people?) it might mean that every single moment of their life outside is being recorded, which was literally not possible until recently. It's a valid thing to discuss.

What I'm against is this idea that X is okay as long as X is expensive, but the moment X becomes cheap, or democratized, or accessible, all of a sudden it's a problem, and we need a ban.

Example: it's already legal to keep tabs on people in public. There are businesses build on this idea, private investigators. A little sleazy? Expensive? Sure. But legal. If you want to be consistent, you should ban them too.

If X is what causes harm, X should be disallowed no matter the price.

In general I disagree (but would agree with you in certain cases, like something that was doable but gatekept due to cost).

Alot of X's aren't a problem until they can scale. It's not pragmatic to outlaw everything that might be a problem at scale but might never be able to achieve that scale.

We're in an era where we are discovering alot of abuses that could only be classified as an issue due to scale and efficiency.

The problem is that many problems are so because of their scale. For instance, you have billions of harmful bacteria in your body, but are (presumably) not afflicted because they can be handled by your immune system. It would be bad to eliminate all the bad bacteria (even if this were possible without killing good bacteria) because your immune system would become more fragile in future infections.

For many things, the scale is the problem.

> What I'm against is this idea that if X is okay as long as X is expensive, but the moment X becomes cheap, or democratized, or accessible, all of a sudden it's a problem, and we need a ban.

These kinds of things tend to increase attention given to issues, yes. I don't think it's unreasonable to think that people care more about things that are easily and practically abused, because, well, those are the things that are more likely to actually affect them. Plus it's a lot harder to argue against some formless "maybe people could be watching me" threat, but a lot easier to reason about a specific example.

> Example: it's already legal to keep tabs on people in public. There are businesses build on this idea, private investigators. A little sleazy? Expensive? Sure. But legal. If you want to be consistent, you should ban them too.

I'm not really a fan of private investigators, to be honest, but I haven't really given it as much thought as I should before I argue my case online.

Some things are actually acceptable, not necessarily good, if only done/available on a small scale. But get problematic once done on a large scale.

Good example is paper records, lots of sensible stuff is recorded on paper records. Access to those is often less than perfectly secured. But, because accessing hundreds of them is tedious, and stealing them might require an actual truck, this is not a real world problem. The moment we digitize this data, it get‘s so easy to access, copy, etc that the old level of access protections is no longer enough.

Similar problem with scaling up face detection. Lot‘s of jerks would surely like to harass other people by following them around everywhere, spying on them and generally make their life’s miserable. Until know, this was really expensive - time and money wise - so it did happen only rarely. But once this gets automated, it also gets cheap.

There are a near infinite number of things that we could pass laws against but don't because it isn't currently an issue. We pass the law when it becomes an issue.

Should we bother passing a law saying it is illegal to teleport across international borders, thus evading immigration checkpoints? Should we set tax rates for the sale and import of time machines? Or does it make sense to wait until either is remotely possible?

"i don't care if i don't have privacy" is not as strong an argument as you think. almost nobody wants strangers to be able to stalk them trivially and arbitrarily.

> I've yet to see privacy advocates identify actual undeserved harms that have come to people as a result of the technology that they want to regulate.

Harms like protesters getting identified, in Hong Kong and elsewhere?

Why do protesters have an expectation of privacy? You go out in public and someone might see you there. If you're a peaceful protester, it shouldn't matter. If you're performing criminal acts while protesting, you should be stopped.

I see a lot of people saying that it's terrible that protesters might be identified. I think at least some of these people are secretly upset that people can't break windows and burn cars with impunity.

> Why do protesters have an expectation of privacy?

You asked about harm. Expectation of privacy is a different matter. And they might expect privacy due to wearing masks - why is it okay to regulate those, but not facial recognition? While I'm against regulating facial recognition, I'm at least aware of the harm it causes.

> If you're a peaceful protester, it shouldn't matter.

It shouldn't, but it does. If the government and corporations were so perfect that it wouldn't matter, you wouldn't be protesting in the first place.

> I think at least some of these people are secretly upset that people can't break windows and burn cars with impunity.

This is a pure ad hominem, and not a very good one either. The motivations of an imagined 'some' people are irrelevant to the harms of surveillance and facial recognition.

Governments might decide they want to retaliate against peaceful protesters, if the peaceful protests are causing problems for their agenda. This would have a tremendous chilling effect on protest.

Governments have retaliated against protesters for centuries. They don't need face recognition to do it. Even now, motivated individuals regularly identify and shame individuals involved in various public demonstrations. I find this fixation on the anti-protest use case of facial recognition to be very bizarre. Is a ban on smart doorbell cameras really going to prevent a state actor doing what it wants?

The gross invasion of privacy is not taking pictures of people in public spaces. It's cross-referencing those pictures against images people have uploaded to various online services, many of them before this kind of use in facial recognition databases had even been conceived by anyone except science fiction writers.

If it's not a privacy violation when I do it with my eyes and my brain, it's not a privacy violation when I do it with my computer.

When lone individuals go trawling social media sites for pictures of some random stranger they met on the street, this is commonly understood as creepy at best and (especially to the extent they are violating the terms of the platforms) an invasion of privacy at worst.