Jonathan Mayer, a graduate student in law and computer science, has attracted worldwide media attention for his investigations into online privacy policies. His discovery that the Romney and Obama presidential campaign websites were leaking visitor information to third-party trackers was featured in a New York Times article, and he has served as a consultant to law enforcement. The Daily sat down with Mayer to discuss his recent work, which includes a patch that will be implemented in the latest Mozilla Firefox web browser, and his ideas for improving Internet security.

The Stanford Daily (TSD): How and when did you become interested in Internet security?

Jonathan Mayer (JM): The first time I realized that it was going to be a potential career was [as an] undergrad when I took a class in information security…I liked that very slight bit of subversiveness that the field has to it. It’s an academic field that is in many ways quite applied, in many ways very much [about] interacting with companies and government…I liked that a lot.

TSD: What brought you to Stanford, and why did you decide to focus on law and computer science?

JM: When I was looking at grad programs, I knew I wanted to do law and computer science…I wound up, in my visit, enjoying Stanford computer science the most and enjoying Stanford law the most, so that made it pretty easy. The hard part was the “choose-your-own-adventure” component of building this program…My understanding was that there was a little bit of administrative scrambling before I showed up on campus, about, “Wait a minute, have we made a tragic mistake? This guy is supposed to be at the Law School. This guy is supposed to be at the Computer Science Department. What do we do?” Stanford, very admirably, figured out what it needed to figure out and has been an awesome place ever since.

TSD: You’ve been featured in the media for your discoveries about how companies track their users on the web—what were your most well-known findings?

JM: One was some research I did maybe a year and a half ago into Safari’s cookie-blocking feature and some companies that are intentionally circumventing that feature, with varying rationales for doing it and varying consequences. One of the companies that was circumventing the feature was Google. That research contributed to a federal regulatory action, resulting in a billing fine of $22.5 million.

The Firefox cookie-blocking feature I was working on certainly got quite a bit of media attention—I think it’s one of the most meaningful things that I worked on. The feature initially was very quiet, and that was fine with me…It was only when it finally landed in a pre-released version of Firefox when the media attention picked up…There were some very entertaining reactions from some folks. Someone called it [a] “nuclear first strike.”

I spent some amount of time collaborating with the California Department of Justice on an initiative to facilitate putting privacy policies in mobile applications. That’s an initiative that I think all of the major mobile app platforms have now signed on to. I think it was a really great success with regulatory agencies doing things on the cutting edge, where historically speaking, regulatory agencies have had a tough time…I don’t think I would have had that opportunity had I not been at Stanford.

TSD: How have you been working with Mozilla to integrate your technology into its new browser, and when did they become interested in your technology?

JM: Security and privacy space is not that big. It’s a little bit of an “everyone-knows-everyone” community after you have been around for a while…I and some others have, over the course of the past year, kicked around some ideas with Mozilla about some technical countermeasures that Mozilla Firefox can include. One of those directions was revising the cookie policy.

It’s looking good, but we want to be sure, be rigorous…as we add more things—for example, what about sites that users only visit once and never come back to? The policy doesn’t have any special provisions for that. What about old cookies? So if you have an older version of Firefox and update to this policy and you have tracking history [from] before, what are we going to do about that? That’s sort of a flavor of the sort of things that we’re going to think through.

 TSD: What do you think is the most important thing that Internet users should do to protect their privacy?

JM: I wish there was an easy answer. That’s one of the reasons why I think working on the Firefox cookie policy has been one of the most meaningful projects I have worked on—it puts privacy in hands of users. Firefox has something like 400 million-plus users. By default, those users are going to get this new privacy feature. There is an enormous body of research on how existing privacy tools and security tools are really hard to use and consumers and enterprises really don’t understand them. If you do understand them, they are really hard to get configured and kept up to date. That’s one of the reasons I was working on this Firefox feature and working to make that exist.

This interview has been condensed and edited.