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Subject: Woman's man
Time to talk: None.China can apparently now identify citizens based on the way they walk
151–160 of 180 posts
Re: China can apparently now identify citizens based on the way they walk
#152I made a couple trips to the South Pole in grad school. Down there you were either a scientist in a red parka, black insulated pants, and white boots or support staff in brown carharts. No part of the body could be seen at a distance and even the gloves were standard issue. What constantly amazed me was how you could see someone walking a quarter mile away and instantly know exactly who it was. The South Pole is a sm…
> The South Pole is a smaller population than China so I'd be worried about false positives
Even if the false positive rate is really low, it's still a problem. All of these dragnet-style things mess with your priors. In a traditional investigation, the police have a handful of suspects and then gather evidence. Circumstantial evidence showing that the chances are 1 in 1000 that this one of the five suspects was not the culprit is pretty convincing, and probably enough to convict.
Cast a dragnet over a city of 1 million, and suddenly that same 1-in-1000 error rate will be giving you 1000 innocent people who, under the old system, are 'guilty beyond reasonable doubt'. They've been pre-selected to look pretty frikkin' bad regardless of whether they're guilty, which means any one of them will have a hell of a time proving their innocence.
Re: China can apparently now identify citizens based on the way they walk
#153Earlier quoted context omitted.
> you just can't care about all movement of all cars Of course we can. For each license plate encountered by CCTV or cop cars, store a tuple of (timestamp, coordinates). This won't require much disk space, so that's not a concern. Later, it is easy to answer questions like "what places was this car seen and when?" and "which cars were in this vicinity at this time?"
Well, let's test your claim. Say there are 1 million cars in a city. Say your camera system covers 300 square miles (to handle nyc). The question is how long would it take to scan the images from a single moment and capture all license plates. At 5 seconds per plate, that's 57 days. Plenty of time to commit a crime and escape without detection. And again, you could've been doing something useful like capturing some l…
Why would it take 5 seconds a plate? They could as well station a licence plate reader at each intersection, and update a key-value store with a given plate's last seen location whenever one is spotted. O(1).
Re: China can apparently now identify citizens based on the way they walk
#154One of the books I read when I was younger that got me into programming is Little Brother by Cory Doctorow. In the book, the high school they attend has cameras that identify students by measuring gait. The characters in the book put gravel in their shoes to throw the tech off when cutting class.
Re: China can apparently now identify citizens based on the way they walk
#155I made a couple trips to the South Pole in grad school. Down there you were either a scientist in a red parka, black insulated pants, and white boots or support staff in brown carharts. No part of the body could be seen at a distance and even the gloves were standard issue. What constantly amazed me was how you could see someone walking a quarter mile away and instantly know exactly who it was. The South Pole is a sm…
Former Polie (10x; IceCube) - I also noticed this there. I wouldn't trust it 100%, but it was pretty reliable. I expect that if you knew that the cameras were watching, you could trick their AI's pretty easily (e.g., by faking a limp), but I'd prefer to confirm that before relying on it :-).
Detecting an unnatural gait is probably a fairly easy AI task, unfortunately.
Kind of reminds me of Dunes "Walk without rhythm so you don't attract the worm"
Re: China can apparently now identify citizens based on the way they walk
#156Earlier quoted context omitted.
Well, let's test your claim. Say there are 1 million cars in a city. Say your camera system covers 300 square miles (to handle nyc). The question is how long would it take to scan the images from a single moment and capture all license plates. At 5 seconds per plate, that's 57 days. Plenty of time to commit a crime and escape without detection. And again, you could've been doing something useful like capturing some l…
Why would it take 5 seconds a plate? They could as well station a licence plate reader at each intersection, and update a key-value store with a given plate's last seen location whenever one is spotted. O(1).
Parallelization you say? 5 seconds is constant time, and a pretty optimistic one. How many license plates are visible from any given intersection in my town, NYC? Somewhere between 5 and 50. There is always motion, so what should the frame rate be? You probably can't commit much of a crime in 15 seconds, but you can drive an 8th of a mile (at 30 mph), about two intersections. So let's settle on a frame rate of 5 seconds. You still won't have much precision with cameras only at each intersection, so let's put them 10 feet apart, and let's have 4 at each point. Honestly, that's a minimum. At 10 feet apart, for NYCs 6074 miles of road, that's 12,828,288 computerized cameras. That's about $12B. And I still bet that the error rate will be too high to be useful.
I'm not arguing that it will never be possible, I'm arguing that the original claim, and the mass surveillance that make people nervous, is not happening today.
Re: China can apparently now identify citizens based on the way they walk
#157Setting who wants to do this aside in order to avoid the constant 'X is worse than Y' arguments. I don't think it's unreasonable to assume that in a near future we will have cameras that can do much more than identification on a massive scale. It may be easy to track things like how stressed, healthy, sober etc. people are without their consent or without them even noticing. And this would be precise , not speculativ…
Yup. Think about how you can recognize your friends without even seeing their face, by the way they walk, what they wear, how tall they are, and other contextual clues. Computers will be able to do all of that. Also think about other things that only computers with massive amounts of data will be able to do. Computers will be able to enumerate your wardrobe, your possessions. They'll be able to figure out most of the…
You might also think about how often you walk right past your friends without recognizing them.
Re: China can apparently now identify citizens based on the way they walk
#158I made a couple trips to the South Pole in grad school. Down there you were either a scientist in a red parka, black insulated pants, and white boots or support staff in brown carharts. No part of the body could be seen at a distance and even the gloves were standard issue. What constantly amazed me was how you could see someone walking a quarter mile away and instantly know exactly who it was. The South Pole is a sm…
> The South Pole is a smaller population than China so I'd be worried about false positives Even if the false positive rate is really low, it's still a problem. All of these dragnet-style things mess with your priors. In a traditional investigation, the police have a handful of suspects and then gather evidence. Circumstantial evidence showing that the chances are 1 in 1000 that this one of the five suspects was not…
I suspect there’s quite a bit of case law on what probability of false positives is acceptable?
Re: China can apparently now identify citizens based on the way they walk
#159Earlier quoted context omitted.
The US is still actually pretty good to it's citizens by global standards. For example as an American I don't have any worries that the government will come after me if I speak out against it and a politician can't have me thrown in jail without a trial. But I mean of course as an American I would care more about what the US does because it affects me more. The war on drugs especially is an authoritarian nightmare (a…
USA Drug War was always meant to be racist, and it always has been. See the statements of e.g. Anslinger and Nixon. Seeing mere contingency where intent is clear is a tawdry sort of privilege.
I was just making a weaker claim because honestly I didn't have enough time to properly defend a stronger one on the internet and in my experience ascribing racism explicitly to things takes a lot of effort to defend (though in this specific case that isn't true). Apologies if it was insensitive.
Re: China can apparently now identify citizens based on the way they walk
#160Earlier quoted context omitted.
Former Polie (10x; IceCube) - I also noticed this there. I wouldn't trust it 100%, but it was pretty reliable. I expect that if you knew that the cameras were watching, you could trick their AI's pretty easily (e.g., by faking a limp), but I'd prefer to confirm that before relying on it :-).
Detecting an unnatural gait is probably a fairly easy AI task, unfortunately. Kind of reminds me of Dunes "Walk without rhythm so you don't attract the worm"
Reminds me of Dune before Butler's Jihad.