Facebook users will begin finding out on Monday if their personal information was given to Cambridge Analytica, the London-based political data firm hired by President Trump's 2016 election campaign, ABC News reports.
The information leak affected 87 million people, according to Facebook, with the bulk of the users – 70 million – living in the United States.
You'll know if your info was harvested if you have an alert at the top of your news feed, although it's unclear if everyone will be informed on Monday or in a longer, drawn out time period.
According to CNN, the data was collected by University of Cambridge psychology professor Aleksandr Kogan, who then gave the information to Cambridge Analytica – a move that Facebook has since said violated their terms of service with Kogan.
Data that was shared included details on user identities, friends, and things users "liked," among other information.
That data was then used to target users specific advertisements, The New York Times reports.
Facebook has since said its making its privacy tools easier to find and use. You can read up on how to do so right here.