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Comment by anabis | Hacker News Reader

In Japan at least, before automated facial recognition, cashiers recorded buyer demographics by hand. I would think other places do it too.

Edit: Here is what the buttons look like. Gender and age. https://image.slidesharecdn.com/hvc-c-android-prototype20141...

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I've seen this in Canada, at a Dairy Queen.

The cash register had a matrix of buttons

M: [0-9][10-19][20-29][30-54][55+]

F: [0-9][10-19][20-29][30-54][55+]

They'd just push a button as they punched in your order.

Presumably most cashiers would just optimise to pressing the same button on every transaction, since doing it "right" makes no difference observable to them.

Unlikely to be common behavior. The tally would come back at the end of a shift or day and the person doing that would be reprimanded, then fired if it continued. It would be enforced by the manager/s.

Now, would they press a random demographic button after that (instead of the same button every time)? Maybe, however there are numerous other ways to increase compliance in that case as well. If the logs kept coming back sketchy, well the cashiers are on tape - bam, another firing (note from the video tape: cashier intentionally hits male button when it's obviously a female, then repeats the behavior multiple times). Eventually the example gets across to the other workers to at least make an effort.

You're giving the organizations too much credit. A roommate of mine worked at a fast food restaurant in the early 2000s, where they were measuring the speed that workers took orders by timing the transactions on the cash register. The store manager had the brilliant idea to game it by running all cash transactions on pen&paper - not using the register at all! not even the cash drawers! - and then keying in the orders as fast as possible after the fact. The store won an award, the manager got a big bonus.

Hah, that's brilliant.

In a few stores here in Australia, I am asked for my post code (or country of residence if no post code) by the cashier when ringing up a sale. Predominantly at tourist/tour related points of sale, but I've also had it an electronics and white goods stores.

No idea if the operator is also recording gender and perceived age group etc., but I do know that on most occasions, you can opt not to answer the post code question.

I'm not sure if it's true, but a friend once told me the reason a store asked for your zip code was to see if they had a large audience coming from a certain area. This let them know other locations to possibly open other stores.

The GM of the big box that I worked at 25 years ago said that the zip code thing was to measure the "destinationness" of the store.

In our case, the average big ticket buyer travelled an average of 30 miles, which was awesome in that it made the end caps more valuable.

I've heard (unsure if true) it was to reduce entropy.

IE they keep the last 4 digits of your credit card, combined with a post code you have a unique id.

Not necessary, most point of sale systems can provide a unique hashed or tokenized version of the account number for analytics and identification purposes.

As far back as 2000, my partner was asked for her zip code as we made a purchase and I curtly replied "no comment," to the surprise of everyone there. She walked for her phone number, which really irritated me because this was a $5 retail purchase of some type), and I got more curt when I said, "You don't need that!"

I've been annoyed by this stuff long before most people were ready to consider privacy concerns anything more than paranoia.

I like to give fake numbers in these situations. The way I see it, intentionally supplying bogus data is one of the only ways we have left to fight the machines and their algorithms!

My father had memorized a fake Social Security Number that had come as a sample card in a wallet he got in the 1950s. When anybody except the government asked for his SSN and who wouldn't relent on his pushback, he would give them that number.

It wasn't 078-05-1120?

https://www.ssa.gov/history/ssn/misused.html

Wow, nice! I don't know if he was one of the 12 in 1977, but he would have been if this is the number he used. Woolworth's totally makes sense. If he were alive, he would poop purple Twinkies at that story. Thanks!

How does that work for him for things that do credit checks?

He's been dead for 10 years, but he didn't use it for those. As I remember it, in the 80s-90s it was more common for SSNs to be requested for normal consumer things.

!!!!!!! Can't wait for those numbers to leak out!

I gotta say, it's possible he never actually used it in my lifetime, but he could sure tell that story and rattle off the digits at a moment's prompting.

I like to give obviously fake numbers. Like 12345 for a zip code or 212-555-1234 for a phone number. Most people don't care enough to have a reaction, now and then you get a laugh, and rarely you'll get someone who calls it out as bogus. My standard retort is somewhere between "Are you saying I don't know my own phone number?" and "Are you calling a liar?!" depending on how surly the response.

I was in an albertsons back when they wanted a number in tahoe and went in the 2nd time... cashier remembered me and said "what's that number again... something something something 5309eynine..." and was dancing a bit... it took me a second then I said "what's the area code here?" he glady gave it to me, so for about 12 years I just did $CURRENT_ZIP-867-5309.

My safeway card is in someone else's name... one day they had to pull it for some reason and I got a "Have a nice day.... Mr.... Soprano." and a big smile.

Some countries have law making it illegal to give bogus information about you, with hefty fines and jail time.

There's a bit of plausible deniability if you give slightly bogus info, like transposing numbers. You could assert that there was a typo on the company's part.

Really? I say "Nope" constantly and they're like "no problem" or "it's way easier to look up refunds that way" which is true depending on the store.

> "it's way easier to look up refunds that way"

"Thanks good to know, from now on I'll go buy at a business where this artificial limitation does not exist."

If you purchased with a card, they can usually look up a transaction based on that.

Sometimes the credit card terminal will ask especially at gas pumps for my zip code as an anti fraud measure, and will reject the transaction of you enter the wrong number. If a cashier is asking I always use 90210.

I had same issue when visiting the US. I tried some fake numbers but it wouldn't accept it (my actual postal code has letters, so that wasn't possible), so I just ended up paying by cash.

Did you try your postal code minus the letters? Afaik[1] usually only the numbers in your address are verified anyway.

[1]: https://en.wikipedia.org/wiki/Address_Verification_System

My UK postal code only has two numeric digits, whereas I seem to recall the US gas pumps require five digits. Just means you can't pay at the pump.

Post codes in Australia are just 4 numbers, so when buying subway tickets in NYC, I just put in 10000 or something (I believe that's close enough to the local code?).

I guess a lot of people not from the US will use 90210 when prompted for a US postal code. I can't even remember what the show was about (except that it was set in Beverly Hills, obviously), but the number stuck.

The show was called 'Beverly Hills 90210'

Just a generic teen drama

I always give the post code of the shop, if I know it, or one nearby that I do know.

Wait, why do you know the post codes of the places you shop?

Wait, you don't? :-)

Seriously, I mostly shop in the same neighbourhoods. And when not, there's often something on the counter with their address...or I can give a mate's address and let him get the junk mail....

By cross-referencing your name (from your credit/debit card) with your zip/post-code, stores are able to determine specifically who you are with greater probability than without the zip/post-code.

This is the correct answer.

With near 100% probability actually. There was a detailed report on that few years ago.

Googling for "why stores ask for the zip code" brings up a lot of press post, e.g. https://www.forbes.com/sites/adamtanner/2013/06/19/theres-a-...

Isn't it a credit card security feature? That's what it's for at gas stations.

I think they mean if a salesperson asks you for it, rather than when you put it in for a credit transaction.

Correction, that what they pretend it is for at gas stations.

99,99% of the time when asked a piece of personal data it is for cross-referencing or other privacy invading purpose.

Of course you can refuse, but you can also just give them a false one.

When you go to those weekend open inspections in Sydney, you are almost guaranteed to be asked for your postcode. They record that as well.

I actually did some experiments - for different properties in roughly the same area/price range, I told different real estate agents different postcodes. It is beyond reasonable doubt that the code you tell them play a huge role on how they rank you as potential buyers. When you tell them a random north shore post code, you are guaranteed to receive a nice & friendly follow up on the coming Monday, however if you tell them that you live in the west (when mostly inspecting north shore properties), they would smile and immediately end the whole conversation.

The sample size here is ~50, which I believe is big enough to draw some reasonable conclusions.

If you give them a mobile phone number (which they all ask for) they will simply use that to track you far more closely than than can with a postcode

How? As far as I know a commercial company can't get your location or other personal information just by knowing your mobile phone number?

You are fooling yourself here. They probably have a whole data cake already, they want the mobile number as a cherry topping on this cake.

You know about the anonymized and aggregated data that one can buy ? Well it can be easily anonymized and deaggregated.

The good part is that you don't even have to do it yourself and go directly to data brokers that have done the hard work for you.

Coming from the standpoint of a very curious independent researcher, I'm curious what I might query/search for to learn more about these data brokers.

Not at all out of anything that might be categorized as malice, just to add this datapoint to my mental map.

Buying data lists. You usee your mobile number to get your cinema ticket - or whatever - the cinema sells that data. Do you get package alerts when you have a parcel due, now your phone number is joined to that address, plus presumably the credit card companies sell their data (?).

Companies amalgamate that data, then sell lookups of varying degrees.

Screwfix in the UK gather a lot of personal data as part of their sales process, they're the least covert about data gathering I've seen.

Don't forget loyalty cards are both a way to track demo and purchasing trends.

I volunteer at the Boston Museum of Science on Sundays and we also track how many people we interact with at the various activities. We log by group, so log might read "1 man, 1 woman, 2 boys, 1 girl (family)" or "3 women, 10 girls, 12 boys (school group)"

It's really handy to see how many people the activities attract, and who they appeal to most. You're tracked everywhere!

Could you be more specific? What could they possibly [Edit:] have recorded in a second other than male/female, Japanese/foreigner, or child/adult?

Facial recognition is a unique identifier but cashiers have access to almost nothing they can record... [Edit] What was it?

Edit: clarified that I am asking about the history here, what information was manually collected by cashiers as parent stated

Demographics and sales data is a primary example of big data.

The tweeted advertisement system also looks like it's only recording demographics. Not individual personal IDs.

Sorry, I wanted you to expand on this: "cashiers recorded buyer demographics by hand".

Give me an example of what they used to record by hand. All I can think of is "male, adult". I am specifically interested in what else you say they used to record.

I wasn't asking about the present status quo, only your historical statement about cashiers recording by hand.

Oh, OK. I edited in a link to the buttons the cashiers used, in the original post.

Thank you! Obviously that is far less privacy violating than demographics could be.

Today advertisers that phone home (spyware) often lie and claim only aggregate data is produced - but this manual example really is the kind of data that is okay. It's far less detailed than something like facial recognition. Thanks for adding the link!

You could distinguish people who are married or are parents (with false negatives) by recording people who are at the till with their spouse or children. (Send out demographic-research cards once, to a few of the same stores you've collected this info from, to derive a normalization factor that will make such collected observations useful from then on.)

You could make a note of a person's seeming affect—positive/negative/neutral emotion.

I'm asking historically what was actually done, not what could be done. (For, "what could be done" you could ask if the cashier had seen this person before? Are they a regular shopper here, as far as the cashier notices?) I am asking what information cashiers in Japan actually in fact recorded by hand. What did these cards look like for each customer. Etc.

Generally what has been "accepted" as done is age and male/female. I'm sure some places have done more but that's all I've heard of (lived in Japan for about 6 years now).

Image of actual buttons used added to the original post.

Keep in mind this has to be done while doing usual cashier things, so not much attention can be taken up by it.

Thanks!

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