In 2014, a researcher named Alexander Kogan created a personality quiz that 270,000 Facebook users would go on to install. From those downloads alone, he was able to harvest the personal information of up to 87 million people, according to Facebook's most recent estimate. He then passed that data along to Trump-affiliated political firm Cambridge Analytica, which would use it to target voters in the 2016 presidential election. Now Facebook has finally released a tool that lets you know whether you were affected.
Beginning at noon EDT on Monday, some Facebook users will see one of two messages at the top of their News feed. Both use the header Protecting Your Information, with one focusing on Cambridge Analytica and the other providing more general guidance about controlling which apps and websites currently have access to your data.
It appears that only those who were friends with someone who used Kogan's app—called "This Is Your Digital Life"—will see the Cambridge Analytica warning.