Here’s why you really shouldn’t ignore that pop-up from Facebook

If you’re an internet user, chances are you’ve recently been getting heaps of emails and notifications from your favorite apps and newsletters you might not even remember signing up for, asking you to opt in to keep getting marketing emails. Facebook $META is no exception.

Facebook has been showing pop-up messages to EU citizens about how it is using their data, and asking for continued access to the information it has on them. The company is obliged to do this for EU users under a new law, referred to as the General Data Protection Regulation (GDPR), which companies have to adhere to by Friday, May 25. Following scrutiny of its data practices, Facebook had also promised that it would make the controls it introduced for GDPR available to users worldwide. And on May 23, it announced that it would start showing similar pop-ups to users outside the EU.

The main difference between what Facebook shows EU users and those outside the region is that EU citizens have to click through the agreements in order to keep using the platform, while everyone else can ignore it, a spokesperson for the company told Quartz.

Here’s why you shouldn’t.

The pop-up that will appear in your feed starting this week will tell you several important things about how Facebook uses your data, which you might not have been aware of:

• Facebook will describe how it uses data from its “partners”—advertisers, app developers, and publishers—to show you targeted advertising. It’ll direct you to the settings that let you opt out of targeting. (Here’s a full guide on how to erase your ad preferences.) Facebook argues that targeting makes ads more relevant to users, but the practice is at the center of multiple controversies, including Russian meddling in the US election, advertising discrimination, and the recent Cambridge Analytica scandal.
• The pop-up will show you what kind of political, religious and relationship information Facebook knows about you. Perhaps you added all this when you signed up for Facebook years ago, and forgot that it was there for anyone to see—this will be a useful reminder in case you don’t want this kind of sensitive information online. Facebook admitted last month that nearly everyone’s public profile has been scraped by third parties at some point, so you should assume this information is already out in the world.
• It will also tell you whether or not you’ve opted out of Facebook’s facial recognition technology. Every time someone uploads a photo of you to the platform and tags you in it, it helps the company build a massive database of, well, faces. Facebook has gotten into hot water in the past for gathering users’ face data without their consent. If you’ve already disabled facial recognition, you won’t be asked to turn it on again,