The Cambridge Analytica scandal and Mark Zuckerberg's subsequent testimony has set off a million questions in the public's mind about what data Facebook has on them. Here's how to check what Facebook knows about you, despite your privacy settings.

These sites and apps will tell you what you should know about Facebook before you use the social network. If you only want to know whether your data was leaked, check Facebook's Cambridge Analytica tool.

Let's take a look at what Facebook knows about you and what you can do about it.

1. Sign Up For Facebook (Web): Plain English Revelation of Facebook's Terms

Sign Up for Facebook explains Facebook's terms and conditions in simple terms

Before you signed up for a Facebook account, you agreed to certain terms and conditions. It was one of those long, legalese tabs that you didn't pay attention to and just clicked "Continue" on. Well, that document gave Facebook a lot of power.

The average person finds it difficult to read and comprehend the terms of service. So developer Marten Bjork launched a simple page that puts all of Facebook's privacy-hijacking terms in plain English. This is what you should know about Facebook before signing up and using it.

Each line explains what you need to be okay with if you want to use Facebook. Every point is backed up with links to Facebook's policy page, terms of service, press releases, or third-party articles from reputed sources.

All put together, it's a good explanation of all the hidden clauses that go into using Facebook. This would be ideal before you sign up for Facebook, but even if you already have, the information here might make you think twice about using the social network.

2. Off Facebook Activity (Web): What Other Apps and Sites Tell Facebook About You

Off Facebook Activity lets you view and control what facebook knows about you through third party websites and apps

It is no secret that Facebook is always tracking you, even when you aren't using the website. Third-party trackers give it unprecedented access. Well, the social network itself launched a tool for you to check what Facebook knows about you through these apps and websites.

Go to Facebook > Settings > Your Facebook Information > Off Facebook Activity or follow the direct link above. Any app that you logged in to with your Facebook account will show up here.

In Access Your Information and Download Your Information, you can see and save all the data that these apps and websites are sending to Facebook. It goes back years and years, the scrolling might shock you.

If you're uncomfortable with this much data being given to Facebook, go to Manage Future Off-Facebook Activity. This will let you log out of all these services in one click.

You can also enable or disable apps individually, which might be the smarter move if you use Facebook as your primary login on several favorite apps. Learn more about Off-Facebook Activity to find out all it can do.

3. Jumbo (Android, iOS): Simplest Way to Understand and Act on Facebook Privacy Settings

If the Facebook privacy settings are confusing for you, get Jumbo. This privacy-focused app has the simplest explanations for what Facebook knows about you, as well as several other popular online apps. You need to pay to unlock many of the other apps, but the Facebook scan and recommendations are free.

Once you log into Jumbo, it takes a few minutes to figure out what privacy settings you've got on Facebook. Then, in individual cards, you can check what Facebook knows about you. For example, Facebook stores all the searches you have done. In one tap, Jumbo can delete these without ever exiting the app.

Jumbo goes through your profile and recommends deleting some old posts, which you can backup in the app. It'll show you how many advertisers are showing you ads based on your contact info, which again you can stop tracking in one tap.

Is Facebook tracking your activity on partner apps and websites? Do search engines link to your profile? Are friends able to see anything you post, or what others post on your timeline? With Jumbo, see what Facebook knows about you and take action.

Download: Jumbo for Android | iOS (Free)

4. Facebook Container (Firefox): Sandbox Your Identity

Mozilla's Facebook Container is a Firefox extension to create a sandbox in your browser, keeping Firefox from tracking other tabs

While we have covered both of these tools in detail before, it's important to talk about them again in the current context. Facebook Container and Privacy Badger are both browser extensions that stop Facebook from tracking you across your web browsing session.

Facebook Container is made by Mozilla to stop tracking on Firefox, so there isn't a Chrome version yet. The extension creates a "container" for your Facebook session, which means your Facebook login is separated from the rest of your Firefox browser.

It limits what Facebook knows about you, but it only limits a small part of their data collection.

Download: Facebook Container for Firefox (Free)

5. Privacy Badger (Chrome, Firefox): Stop Facebook Tracking

EFF's Privacy Badger extension stops Facebook from tracking you to know more about you

Privacy Badger is made by the Electronic Frontier Foundation (EFF), an independent privacy advocate. The extension shows all the trackers Facebook is running across your browsing session to gather data about you. It works intelligently in the background to thwart Facebook as much as possible so you don't have to lift a finger after the initial setup. Plus it does a lot more than stop Facebook alone.

Download: Privacy Badger for Chrome | Firefox | Opera (Free)

6. Delete Facebook (Web): How to Finally Pull the Plug

If you're concerned about how much facebook knows about you, Delete Facebook blog shows how to remove it from your life forever

Given what Facebook knows about you, we wouldn't be surprised if you want to delete your account. While there are still reasons to use Facebook, the #DeleteFacebook movement wants you to get rid of your account altogether. If you're ready to pull the plug, here's the site to know how.

Delete Facebook is an up-to-date guide on how to delete your Facebook account safely and securely. It provides answers to all your questions about the deletion process, along with step-by-step instructions on how to do it. There is also a video guide if you like a visual aid.

Why is this site needed, you ask? Because Facebook makes it ridiculously difficult to delete your account. It will try to play with words to get you to "deactivate" instead of deleting the account, so your data still stays online. Or it will take a login attempt as a sign that you want to cancel your deletion request. Heed Delete Facebook's warnings and instructions and you will finally be able to get rid of it.

Even If You Don't Have Facebook, Facebook Knows You

Here is the kicker. Even if you haven't signed up for Facebook or have deleted your account, that doesn't mean the social network is done with you. By using information from your friends and family, it has created a profile of you without any page to show it. The moment you sign up for an account, it will push all that data to you.

Frightening, isn't it? Read more about these "shadow profiles" on Facebook.