Why did Bradley Cooper and Jessica Alba fail to record a tip when they paid their cabbies during New York City taxi rides back in 2013? Why was Cooper near a Mediterranean restaurant in Greenwich Village? Why was Alba at a ritzy hotel in Soho?
We dont know the answers, but we do know exactly when and where the movie stars were going. And we know all of this not from some special government sting operation but from publicly available data about millions of peoples movements throughout New York City.
That information, released in an open records request, validates the concerns of those who argue that while consumers digital metadata may seem to be anonymous, it actually isnt. It takes just one or two other pieces of information to turn seemingly anonymous branches of metadata into specific information about individuals and not just those who are famous.
In the case of the taxi info, data analyst Christopher Whong filed an open records request in March, 2014 for New Yorks database of cab fare, tip and location information after seeing a tweet from the citys Taxi and Limousine Commission.
Though that database of 174 million cab rides in 2013 includes no passenger names, software engineer Vijay Pandurangan was able to link the data to other publicly available information about license plates, cab driver identities and taxi companies medallion numbers.
Then, to show the individualized surveillance power of the seemingly anonymous data, Anthony Tockar of Neustar Research cross-referenced the information with publicly available photos of celebrities getting into cabs with identifiable license plates.