Thanks to a massive leak by low-level hackers, the data of half a billion Facebook users has been exposed.

According to Business Insider:

The exposed data includes the personal information of over 533 million Facebook users from 106 countries, including over 32 million records on users in the US, 11 million on users in the UK, and 6 million on users in India. It includes their phone numbers, Facebook IDs, full names, locations, birthdates, bios, and, in some cases, email addresses… 

A Facebook spokesperson told Insider that the data had been scraped because of a vulnerability that the company patched in 2019.

The breach was discovered on Saturday by Alon Gal, the chief technology officer for cybercrime intelligence firm Hudson Rock. On Twitter, Gal called the leak an demonstration of “absolute negligence” by Facebook, and also told Business Insider:

“Individuals signing up to a reputable company like Facebook are trusting them with their data, and Facebook [is] supposed to treat the data with utmost respect. Users having their personal information leaked is a huge breach of trust and should be handled accordingly.”

The good news

There’s a super easy way to check if you’ve been hacked: simply enter your email on the website and it will tell you if your email has been compromised.

The bad news

That website will only tell you if your email has been compromised – not whether your phone number or other credentials are at risk. Considering the fact that emails comprised a small percentage of the data leaked in the Facebook breach, there’s a good chance your other data may be at risk even if your email is safe. CNN explains:

Although 533 million Facebook accounts were included in the breach, only 2.5 million of those included emails in the stolen data. So you’ve got less than a half-percent chance of showing up on that website, even though you’ve got about a 20% chance of being hacked if you’ve got a Facebook account.