Personal information of about nearly 50-million Facebook users might have been used improperly.

The Observer reported that Cambridge Analytica, a political consulting company based in London, but with offices in New York and Washington, D.C., collected troves of information from unsuspecting Americans – ranging from their activity, interests, check-ins, locations, photos, religion, politics and relationship details – to create psychographic profiles about voters.

Early on during Facebook’s inception, the company realized they needed to catch up with their competitors and move with users as they began to use mobile devices more frequently.

As a result, they built a platform that allowed developers to integrate their applications with the service.

At that time, the company is said to have been “extremely friendly to app developers,” providing them with access to use their overly permissive Graph API. Doing so was important in their continued growth.

Cambridge Analytica’s initial idea to use Facebook data stemmed from a project just as the company was starting. Facebook was an easy target to collect data – they created a personality quiz, of sorts, which required users to connect their accounts to the quiz.

By doing so, the company was able to not only snatch up information about the user who had made the connection, but also their friends. Only about 270,000 people initially took the quiz, but a resulting 50-million people had their information gathered by the company.

Rather than deleting the information once they were finished, the company stored it in a database for later use. After hearing about this, Facebook immediately demanded Cambridge Analyticaa remove the saved information – which they say they did.

But recent reports by ex-employees say that it’s just not the case.

“We spent a million dollars harvesting tens of millions of Facebook profiles, and those profiles were used as the basis of the algorithms that became the foundations of Cambridge Analytica itself,” said Christopher Wylie, an analyst and Cambridge Analytica co-founder.

A popular photo seen floating around the internet over the weekend depicted a man wheeling tubs of supposed information from the company in an attempt to remove it before they were served with a search warrant.

This scandal is also raising concerns about how voters were influenced during the Brexit vote.

Mark Zuckerberg’s former mentor, Roger McNamee, said that this has been one of the biggest issues for a technology company to face. This comes after Zuck was found to have called about 4,000 Harvard students “dumb f---s” for trusting him with their information during the early years of the website.

Events such as these serve as a great reminder to check which applications have access to your data. Just as the #DeleteFacebook movement expands, many have opted to simply disable the Graph API functionality within Facebook – a feature that can be disabled through settings.

You can also disable specific apps also through your user settings.