Privacy challenges: Just four vague pieces of info can identify you, and your credit card

[Panich52]

Just four fairly vague pieces of information -- the dates and locations of four purchases -- are enough to identify 90 percent of the people in a data set recording three months of credit-card transactions by 1.1 million users. If someone had copies of just three of your recent receipts -- or one receipt, one Instagram photo of you having coffee with friends, and one tweet about the phone you just bought -- would have a 94 percent chance of extracting your credit card records from those of a million other people. This is true, the researchers say, even in cases where no one in the data set is identified by name, address, credit card number, or anything else that we typically think of as personal information.

More:

http://feedproxy.google.com/~r/sciencedaily/strange_science/~3/Ef2S8AUKDRE/150129160856.htm?utm_source=feedburner&utm_medium=email

[SheilaT]

1. Hmmm.

I'm reminded of something I read several years ago that said gender and date of birth coupled with the city you lived in, or maybe it was your zipcode, was enough to identify almost everyone. The only ones it would have a problem with would be same-sex twins who still lived at home or near each other.

[Silent3]

2. It's zip code along with DOB and gender

That date of birth also needs to include the year to narrow a person down so well, but it's still amazing. I think it's something like 70-80% of people can be uniquely identified this way, and nearly everyone is going to be narrowed down to one of no more than three people.

[SheilaT]

5. Thanks for clarifying that it's zip code.

I remember finding that hard to believe when I first learned that, but then I thought about my particular neighborhood, and realized it would be highly accurate. I thought of the twins because the lady across the street had five children, two sets of twins and a singleton. First pair were boy girl, the the second pair was fraternal boys.

However, if the zip code contains enough school-age children, you'll come up with more than one with the same birth date and possibly the same gender. Still, it's pretty amazing, as you said.

[djean111]

3. I used to have a job populating a big database (freebase, unfortunate name, IMO), and

found that there were not many people or things I could not find, or find more info on, if I had three discrete pieces of information about them. More than three was sometimes too much, due to misspellings or accuracy of the data.
And this was eight or ten years ago, there are universes more data out there now.

[SheilaT]

6. I also happen to have a unique first and last name,

so I'm very easy to find if all you know is that.

Everyone with a very common name might be somewhat better off.

[Runningdawg]

4. This is why

I always use cash, and supply personal info on a need to know basis only.
The last time I was confronted by this was at Radio Shack, trying to do a return. The cashier told me she needed my name DOB address, phone # and to see my card to make a refund. BS I pointed out I paid with cash less than 12 hours before and wanted cash in return. She said OK, I don't know how to do that...the manager wanted the same info. Having been in the same situation before, he got his info, it just wasn't mine. They won't be getting anything off a cell either. The only one I have is a burner, kept in a drawer, with no info inside it, used only on road trips in case of emergency.
It used to be true that plastic was great for not loosing cash during a robbery and great that you could then call the police from your cell phone. These days carrying either one is asking to have your entire identity stolen. Forget about that $20 you might have lost in the past, that's nothing compared to what you can loose these days.

[Warren DeMontague]

7. I told Col. Mustard not to buy that candlestick in the living room