The Markup

The Markup is a New York-based nonprofit investigative newsroom focused on how powerful institutions use technology to reshape society. Founded in September 2018 and launched in February 2020, it pioneered two distinct modes of public engagement with algorithmic accountability: a participatory research mechanism that enrolled ordinary users as real-time investigators of platform algorithms, and a series of original investigations into AI-driven discrimination whose policy consequences included a multi-agency federal enforcement initiative and legislative citation in a proposed Algorithmic Accountability Act.

Founding and structure

The Markup was founded by Julia Angwin and Jeff Larson — who had led ProPublica's Machine Bias investigations — and Sue Gardner, former executive director of the Wikimedia Foundation. Craig Newmark contributed $20 million as anchor funder, with additional grants of $2 million from the Knight Foundation and support from the Ford Foundation and the MacArthur Foundation. The organization launched its first investigations in February 2020. Angwin departed in early 2023; in April 2024, The Markup joined CalMatters, a California-based nonprofit news organization, continuing to publish under its own brand within the combined operation.

Citizen Browser

Citizen Browser is a custom browser extension and paid-panelist system built to observe directly what platform algorithms show ordinary users — a participatory research infrastructure with no equivalent in investigative journalism at the time of its launch. A nationally representative panel of approximately 1,200 paid Americans installed the extension, which captured and transmitted their real Facebook and YouTube feeds to The Markup's servers, producing statistically valid samples stratified by age, race, gender, geography, and political affiliation. The panel ran in partnership with The New York Times. In June 2021, Citizen Browser data showed that Facebook continued recommending partisan political groups to its users despite multiple public pledges to stop — twelve of the top 100 recommended groups in the panel sample were political, with political groups recommended most frequently to Trump-voting panelists. Senator Ed Markey wrote to Mark Zuckerberg demanding an explanation; Facebook subsequently attributed the continued recommendations to "technical issues" and stated the problem was resolved.

Blacklight

In September 2020, The Markup launched Blacklight, a free public website-privacy inspector: enter any URL and Blacklight returns which tracking technologies the site deploys — ad trackers, third-party cookies, keystroke loggers, session recorders, canvas fingerprinters, and Facebook and Google remarketing pixels. Built by investigative data journalist Surya Mattu, Blacklight converted a technical capability previously confined to security researchers into a public-facing audit instrument. The launch investigation found that at least 87 percent of the world's most-visited web domains engage in some form of user tracking without users signing in.

Denied: algorithmic mortgage discrimination

The Markup's "Denied" investigation analyzed Home Mortgage Disclosure Act data across the United States and found that lenders were 80 percent more likely to deny Black applicants than similarly qualified white applicants, 70 percent more likely to deny Native American applicants, and 50 percent more likely to deny Asian/Pacific Islander applicants. The analysis identified racial lending disparities spanning nearly every region of the country and attributed part of the gap to Fannie Mae and Freddie Mac underwriting algorithms whose decision logic remains opaque to outside researchers. In October 2021, the Department of Justice, the Consumer Financial Protection Bureau, and the Office of the Comptroller of the Currency cited the investigation when announcing a new multi-agency initiative to combat discriminatory mortgage lending, including digital redlining via black-box algorithms. Sponsors of the Algorithmic Accountability Act of 2023 also cited the investigation as evidence of the need for mandatory algorithmic impact assessments.

Role in the algorithmic accountability movement

The Markup's central design choice — build datasets from scratch, release full methodology and analysis code alongside every investigation, and build public-facing tools that extend the reach of each finding — positioned it as movement infrastructure rather than movement participant. Its investigations anchored two federal enforcement actions and a legislative citation. The Citizen Browser produced documented platform behavior change. Blacklight equipped privacy advocates, compliance officers, and ordinary users with audit capability that previously required technical expertise. The Markup's template extended the ProPublica data-release model into an ongoing public-tooling discipline.