Last week, Facebook confirmed that up to 87 million of its users had had their personal data improperly shared with Cambridge Analytica, a London-based political consultancy.

The social media network had already been under fire for admitting that the data of some 50 million users had been improperly shared, so the new, higher figure spelled even further trouble for the company. The share price of the company plummeted sharply while, in contrast, the #DeleteFacebook movement gained rapid momentum and began trending across other social media platforms.

Mark Zuckerberg, the co-founder, chairman and chief executive officer of Facebook, admitted during a press conference last week that “clearly we should have done more, and we will going forward”. He also said that he was “wrong in retrospect” for believing people were responsible for the way they used Facebook’s “tools”, which ultimately put the responsibility for the leak on the users rather than the company itself. He added, “Today, given what we know… I think we understand that we need to take a broader view of our responsibility.

“That we’re not just building tools, but that we need to take full responsibility for the outcomes of how people use those tools as well.”

Zuckerberg is currently testifying at two congressional hearings about the data breach, during which he is expected to be grilled on the Cambridge Analytica scandal, whether Facebook interfered in the 2016 presidential election and what the future looks like for the company.

As he presents his testimony, some of which you can read on the BBC here, stylist.co.uk explains everything you need to know about the data leak, how to tell if you were affected and, most importantly, how to keep your information safe in the future.

Who was affected?

How to keep your data safe on social media