Just two days ago, Facebook suspended analytics firm Cambridge Analytica's account, along with that of its parent firm Strategic Communications Laboratories (SCL).
In 2015, a Facebook internal report suggested that Cambridge Analytica received data from an app called 'thisisyourdigitallife' developed by Aleksandr Kogan, a Cambridge academic. The app, which required a Facebook login, mined a colossal 50 million Facebook users' private data (which was fine by Facebook, given it didn't breach company policy), and also passed it on to Cambridge Analytica and other third parties with vested interest in the data (which wasn't fine).
When Facebook discovered this, it pulled the app, with assurances from Kogan and SCL that the data was purged from their systems. However, it received recent evidence that these claims were false, leading to SCL and Cambridge Analytica's suspension from the service.
Facebook denied allegations of a data breach in this regard, saying that this information was, technically speaking, shared by users voluntarily.
Given the firm's dubious use of this misappropriated data in Brexit and the Trump campaign, Antonio Tajani, president of the European Parliament, has stated in a tweet that the EU will be investigating these allegations against Cambridge Analytica of its misuse, and Facebook's apparent downplaying of the scale of the issue.