First Known When Lost
Last Thursday the journal Science published an article by four MIT-affiliated data scientists (Sandy Pentland is in the group, and he’s a big name in these circles), titled “Unique in the shopping mall: On the reidentifiability of credit card metadata”. Sounds innocuous enough, but here’s the summary from the front page WSJ article describing the findings:
Researchers at the Massachusetts Institute of Technology, writing Thursday in the journal Science, analyzed anonymous credit-card transactions by 1.1 million people. Using a new analytic formula, they needed only four bits of secondary information—metadata such as location or timing—to identify the unique individual purchasing patterns of 90% of the people involved, even when the data were scrubbed of any names, account numbers or other obvious identifiers.
Still not sure what this means? It means that I don’t need your name and address, much less your social security number, to know who you ARE. With a trivial amount of transactional data I can figure out where you live, what you do, who you associate with, what you buy and what you sell. I don’t need to steal this data, and frankly I wouldn’t know what to do with your social security number even if I had it … it would just slow down my analysis. No, you give me everything I need just by living your very convenient life, where you’ve volunteered every bit of transactional information in the fine print of all of these wondrous services you’ve signed up for. And if there’s a bit more information I need – say, a device that records and transmits your driving habits – well, you’re only too happy to sell that to me for a few dollars off your insurance policy. After all, you’ve got nothing to hide. It’s free money!
…click on the above link to read the rest of the article…
