Cambridge Analytica harvested 87 million Facebook profiles — and Facebook let it happen

In 2018, a scandal broke that exposed how loosely Facebook had handled its users' data. A researcher named Aleksandr Kogan had built a personality-quiz app ('thisisyourdigitallife') that a few hundred thousand people took. But the app also collected data on their Facebook friends — ultimately harvesting the personal information of up to 87 million users, far more than anyone had consented to. That data was passed to the political consulting firm Cambridge Analytica.

Cambridge Analytica used the data for political profiling and targeting, including work on the 2016 US presidential election and the Brexit referendum. When the story became public, it ignited a global firestorm about privacy, consent and the power of social-media platforms. The hashtag #DeleteFacebook trended, and Facebook's reputation for handling user data was shattered.

The fallout was enormous. Facebook's founder Mark Zuckerberg was summoned to testify before the US Congress and the European Parliament. In 2019 the US Federal Trade Commission fined Facebook $5 billion — the largest privacy penalty ever — for deceiving users about their ability to control their data. Cambridge Analytica collapsed and shut down. The scandal became a defining moment in the debate over data privacy and the power of Big Tech.

Facebook's weak safeguards let a quiz app harvest 87 million profiles, leading to a $5B FTC fine and Cambridge Analytica's collapse.

Facebook's platform let a quiz app harvest not just its users' data but their friends' data too, exposing up to 87 million profiles without meaningful consent.

Facebook knew about the data harvest in 2015 but did not adequately ensure it was deleted or notify affected users.

Cambridge Analytica used the data for political profiling and targeting, raising alarms about manipulation of elections.

The scandal exposed a business model built on collecting and monetizing user data with weak safeguards and oversight.

When your business model is collecting user data, every weak safeguard is a breach waiting to happen. Facebook let a quiz app harvest 87 million profiles and never checked where they went.

The Facebook-Cambridge Analytica scandal was a defining moment in the debate over data privacy and the power of Big Tech. It led to a record $5 billion FTC fine, congressional and parliamentary testimony from Mark Zuckerberg, the collapse of Cambridge Analytica, and lasting reforms including the EU's GDPR gaining global attention. The lesson is durable: a platform built on collecting user data must protect it as fiercely as it collects it, because the day the public learns how loosely it was handled, the trust that underpins the business evaporates.