The researchers note that (1) It is definitely possible to target sensitive topics in users’ inboxes, including cancer, depression, or pregnancy. (2) For many ads, targeting was extremely obscure and non-obvious to end-users, which opens them up to abuses. (3) The researchers have already seen signs of such abuses, for instance, a number of subprime loan ads for used cars targeting debt in users’ inboxes. Examples of ads and their targeted topics can be found on the XRay website.
The tool can be used to increase user awareness about how their data is being used, as well as provide much needed tools for auditors, such as researchers, journalists, and investigators, to keep that use under scrutiny. Geambasu and Chaintreau, who recently won a Magic Grant from the Brown institute for Media Innovation to build better transparency tools, have made the XRay prototype available for auditors at http://xray.cs.columbia.edu.