How to see all the companies tracking you on Facebook - and block them

Facebook is great if you want to stay in touch with friends and family. It's free, of course, but it comes with a price. If you're using Facebook, you're giving up a ton of information about yourself, mainly to advertisers who track you.

Most people forget that when they download an app or sign into a website with Facebook, they are giving those companies a look into their Facebook profile. Your profile can often include your email address and phone number as well as your work history and current location. And most people don't realize that if you're sharing that data with friends, then apps used by those friends can see that data as well!

Advertisers, Facebook-app developers, and Facebook ad tech partners can't see your name, your phone number, or your employer - Facebook encrypts and anonymizes all the data to protect your privacy. But it does sell that data in bulk to companies who want to target and track you, and people like you.

If you're worried about your privacy on Facebook, you can do two things:

1. Opt out of ad tracking
2. Look up the list of app companies that are logged in to your Facebook account, and edit that list.

The second step, which shows you just how much info you're giving away to companies you have probably forgotten about, can be rather alarming if you haven't done it in a while.

Facebook tweaked its settings recently, so here is our updated guide to taking care of it all.