One of the features you’ve likely enabled, is Facebook’s platform. To give you an idea of how powerful this is, this is the warning it gives you when you attempt to disable it:

What happens if you disable Facebook’s Platform

So you can consider the inverse of each of these options, when you’ve chosen to enable it. In order to disable it, you need to click on the ? help icon on the top right of your Facebook profile. From there choose Privacy Shortcuts and the bottom, “see more settings. From there click on the Apps option near the bottom on the left. Under the list of apps you’ve authorized, you should see a square that says “Apps, Websites and Plug-ins” at the top. It is there you will find the elusive “Edit” button, where you now have the options to turn Facebook’s platform off.

In case the image above was heard to read, reminder that by turning off Platform you agree:

You will not be able to log into websites or applications using Facebook.

You will not be able to log in to mobile games or applications using Facebook.

Your friends won’t be able to interact and share with you using apps and websites.

Instant personalisation will also be turned off.

Apps you’ve previously installed may still have info you shared. Please contact these apps for details on removing this data.

Apps you’ve logged in to (with Facebook or anonymously) will be removed.

Posts by apps will be removed from your Profile.

but also note that data leakage about your personal information will no longer be shared amongst app developers, or third party websites that allow Facebook login. Also, if you’re Canadian and reading this, you can now go to each one of the apps you’ve previously allowed access to your data, find the privacy officer of that company which they’re legally required to provide, and request that they remove/delete any information they have on you. They have 30 days to respond to your request. If they don’t respond, or their response did not satisfy you that they actually deleted your data as you’ve requested, you can file a complaint with the Privacy Commissioner of Canada.