In 2014, a researcher named Alexander Kogan created a personality quiz that 270,000 Facebook users[1] would go onto install. From those downloads alone, he was able to harvest the personal information of up to 87 million people[2], according to Facebook's most recent estimate. He then passed that data along to Trump-affiliated political firm Cambridge Analytica[3], which would use it to target voters in the 2016 presidential election. Now Facebook has finally released a tool that lets you know if you were affected.

Beginning at noon ET 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.

"We have banned the website 'This Is Your Digital Life,' which one of your friends used Facebook to log into," the message reads. "You can learn more about what happened and how you can remove other apps and websites any time if you no longer want them to have access to your Facebook information."

Those who weren't affected will instead get a direct link to Facebook's Apps and Websites privacy settings, where they can see which apps have access to their data, and the option to remove them.

Facebook

Even Facebook users who weren't impacted by Cambridge Analytica should go ahead and click forward to the Apps and Websites page, a setting that Facebook has inexplicably kept separate from its Privacy options

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