Facebook's Off-Facebook Activity tool is available to people on Facebook around the world, showing you exactly how the social network stalks you — even when you’re not using Facebook.

Facebook’s surveillance is hard to avoid. It doesn’t require you to click “like” or use a “login with Facebook” button. You don’t necessarily have to be logged in to the Facebook app or website on your phone — companies can report other identifying information to Facebook, which will marry up the activity to your account after the fact.

"Other businesses send us information about your activity on their sites and we use that information to show you ads that are relevant to you. Now you can see a summary of that information and clear it from your account if you want to," Facebook CEO Mark Zuckerberg said.

In order to reach people who are more likely to care about what they are selling, businesses often share data about people’s interactions on their websites with ad platforms and other services.

Off-Facebook Activity lets you see a summary of the apps and websites that send Facebook information about your activity, and clear this information from your account if you want to.

With Off-Facebook Activity, you can see and control the data that other apps and websites share with Facebook:

• See a summary of the information other apps and websites have sent Facebook through our online business tools, like Facebook Pixel or Facebook Login;
• Disconnect this information from your account if you want to; and
• Choose to disconnect future off-Facebook activity from your account. You can do this for all of your off-Facebook activity, or just for specific apps and websites.

If you clear your off-Facebook activity, Facebook says it will remove your identifying information from the data that apps and websites choose to send the the social network. The company says it will nor know which websites you visited or what you did there, and that will not use any of the data you disconnect to target ads to you on Facebook, Instagram or Messenger.

Rivals such as Google don’t offer anything comparable to the “Off-Facebook Activity” page.

However, changing these settings doesn’t actually stop Facebook from collecting data about you from other businesses. Facebook will just “disconnect” it from your profile, to use the social network’s carefully chosen word.