Yeah I think this is kinda the danger of these types of systems, and why I don't want to work on them anymore. While I think there are a lot of good uses to this tech, it also has the power to do much more harm and the way I've seen it used even in democratic societies makes me uncomfortable about authoritarian overreach. I could not see a way this can be used in a privacy preserving manner, even for things as simple as counting number of patrons in a store[0]. Right now, I don't feel comfortable furthering this technology in the US, not to mention how I saw it being used elsewhere[1]. I'm sure if you take some time thinking about how the tech could be abused you would find a lot of ways. But it is up to you to decide if it is worth it after doing that exercise (your mind might even change later).

I think this is one of the difficult things about creating things. It is easy to get caught up in the benefits of a technology and how it can be used for good. But technology isn't good or bad, it is a tool. Like any tool, you need to consider how it will be used, and that means how it will be abused. My undergrad was in physics, and this lesson is often taught when you get to atomics (or maybe because my advisor worked at Los Alamos and with many of the people who built the atomic bombs). Physics tends to not hide the skeletons in the closet because atomic weapons. But I think CS still does and maybe we haven't caught up to how influential our work is in modern day. How software can (and does) kill people. Or maybe it is the abstraction of software, working at a high level it is easy to feel disconnected. Either way, I think we need to tread more carefully and just make sure we're concerned about ethics. It is a personal decision where the lines are drawn, but they can't be ignored. After all, the road to hell is paved with good intentions, right? Unfortunately evil isn't only created by evil men, but often good men with good intentions.

FWIW, I'm all for the intent. But I question if there are other ways to solve these issues. But that may require a more complex and nuanced approach[2]. But if enforcement is already a problem, then I think there are bigger problems at play that this technical solution might make worse. Unfortunately as we advance the world gets more complex haha

[0] You can get pretty good if you do upfront processing to blur people, but that first means you need to detect people lol. So this would need to be done on device (as in, the camera itself. Which is possible btw).

[1] I saw a lot of videos from India (as well as the whole subcontinent and South East Asia), where the customers were trying to prevent theft (good usage), but there were some other things that had me concerned and were being hinted at. I also think one big difference is that I appeared to be the only person on my team that would look at data we were processing. Not to snoop or be invasive, but because this is the best way to solve data processing problems; you need to check your assumptions, learn what is creating errors, find things you didn't consider, and all that. To be good at ML you can't just pipe in data and expect results, and you shouldn't treat the algorithms like black boxes. While they aren't transparent ("white boxes"), that doesn't mean they're completely opaque either (and we're learning more every day).

[2] I think one key piece of information is that we need to ask why things like littering and theft is less common in richer neighborhoods. Or at least by their residents. Personally, my belief is that this is more to do with a personal safety net. It's easy for ethics to be eroded when you're worried about your next meal or being able to afford rent. These are obviously harder issues to resolve, but I think they are worth addressing. Because I think lifting up the quality of life of the lowest class of people benefits everyone. A rising tide lifts all ships, and I do believe it even lifts the biggest ships more.