Christopher Wylie, the Cambridge Analytica whistleblower, departs after meeting with House Judiciary Democrats, on Capitol Hill, Tuesday, April 24, 2018 in Washington.

A British political consulting firm Cambridge Analytica illicitly harvested the personal data of millions of Facebook users without their consent to run political campaigns. The scandal came into light after a former employee turned into a whistleblower. This led to several countries re-looking at their data privacy laws and tightening their regulation on tech companies' usage of personal data.

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