This project ended up as a part of Laura Poitras’s show “
Last Seen” at the Whitney Museum. It persistently monitored the visitors to the Whitney show and showed them what their phones were revealing about them.
Angwin: Blacklight was the first persistent monitoring tool you built for journalism. As I recall, I first suggested it to you as an internal tool that we would use to do a privacy census across the web. But you pushed for it to be a real-time forensics tool. Explain your thinking.
Mattu: What I learned from the Wi-Fi project was that people need a narrative to see what is happening in their own lives. I realized that a census was just not personal.
I wanted to up the ante on how to make this feel fresh for users in a way that they would want to engage with the subject again. That’s where my motto to provide readers with “agency not apathy” comes in.
Angwin: What is the technical challenge of taking something from a one-off tool to a persistent monitoring tool?
Mattu: It basically means you age five years in one year! [Laughs.]
But seriously, it was a really interesting process of building technology like a journalism story. Normally an engineer would build a product to focus on the function, but in this case the function was emerging as Aaron Sankin was reporting out the story that would accompany the tool.
Sometimes I would have to throw out a lot of code based on where the editorial process was taking us. For example, when Aaron started talking to website operators, they were really surprised that we had found that their website was setting DoubleClick cookies. They thought they just had Google Analytics.
So we realized we needed to have a test in the tool for Google Analytics being used for retargeting [which is when Google Analytics sets a DoubleClick cookie allowing Google to track users across the web]. From an engineering perspective, monitoring that cookie was the same as monitoring all the other cookies, but from an editorial perspective, monitoring that cookie was enough to make it a separate test.
Angwin: Now let’s talk about Citizen Browser as a persistent monitoring tool. When you and I first started talking about building a panel, I was thinking about a browser extension. And you argued we needed to build a browser because browsers are really good at running persistently in the background.
Mattu: It was basically because I wanted to treat it like actual evidence gathering and in that sense it couldn’t be as opportunistic as a browser extension. From my previous experience—and yours—we knew that people didn’t really use Facebook on their desktop anymore. So building this allowed us to capture data without people having to use their desktop computers to access Facebook.
We wanted to persistently check how things changed on Facebook over time. We were not trying to just build a survey or a census of what is happening on Facebook. We are trying to show anecdotally with real people’s lives what is the difference in how people experience this platform. And to do that, we need to capture a meaningful amount of data over time.
Angwin: What were the challenges of building Citizen Browser?
Mattu: It was difficult to find a way to collect this data in a way that is responsible and first and foremost respecting the privacy of the people sharing data with us. The way to do that was to do some really insane engineering.
We did probably twice the amount of work to ensure we were following all the best practices we could. And we have really constrained ourselves on what we could use because we know that if we don’t do that from the start, we will leak data.
We basically put a guardrail up that we won’t even look at stuff that we can’t report on. You had clarity from the start that we would only focus on what Facebook was recommending. We weren’t interested in how people were using the platform. We were interested in how Facebook was providing information to users.
Angwin: Do you think we will need more persistent monitoring tools in the future?
Mattu: I often think about something you said to us in a call once about how important it is in the digital age to have receipts for the truth. In a world where there is declining trust in journalism, you need to have the evidence to back up the claims you are making.
The reason persistent monitoring is important is that these platforms are constantly changing. Building persistent monitoring tools is the only way to know if the harm you are focusing on is still taking place.