You may have noticed that the sidebar on the right hand side of your Facebook page displays sponsored ads. You may also have noticed that the ads are strangely relevant to your life. That’s not a coincidence. Facebook knows exactly what kinds of ads to show you. It’s called targeted advertising, and it’s more complicated than you think.

It all starts with cookies. Cookies are small files that are stored on your computer and used to hold data that relates to a specific website. Cookies are why certain websites are able to recall your information without you having to enter it a second time. They aren’t inherently bad—in fact, they’re meant to convenience the user. They don’t technically invade your privacy, since they only store information that you’ve already volunteered to a specific website.

Where things get a little tricky is when websites share that cookie information to a third-party for the sake of advertising. This is called ad networking. Ad networks are, well, networks, of websites that pay for advertisement space on popular websites. When you visit one of the members in the ad network, the cookie stored on your computer lets the network at large know exactly which site you visited and what you looked at so that it can send personalized ads to other sites in the network.  

What’s most concerning is Facebook is utilizing these ad networks to personalize those ads on your sidebar. If it were as simple as them getting information from the ad networks, maybe this wouldn’t be as scary. However, Facebook is actively using your Likes, Shares, and even status/photo updates to collect data about you. Facebook looks at the news stories you click on, the people you talk to, and the pictures you like. Plus, Facebook isn’t the only one. Big companies like Google, YouTube, and Amazon participate in target advertising and user data collection, too. They store all of this information in a file, and it helps them target ads just for you.

The bottom line is, as with most things, money. Facebook (and all the others participating in targeted advertising) want to make money off of you. If you click on a sponsored ad on your Facebook page, Facebook gets money. If you purchase something because of that ad, Facebook gets even more money. In 2014, Internet advertisers made almost $50 billion. You can bet that number has only gone up since then.

So, how can you opt out of this tracking and data collection? The truth is, you can’t completely remove yourself from this kind of tracking unless you completely dump all of your technology in the trash. But, you can limit it. If you go to your Facebook settings on your computer, there is a section titled “Ads”. Click into it, and edit your preferences to stop Facebook from showing you interest-based ads. It is important to note that while this won’t stop Facebook from showing you ads based on the things you Like, Share, and post on Facebook, the social media site will no longer be sharing your information with outside advertising companies.

If you want to stop targeted advertising completely, you can visit the Digital Advertising Alliance’s tracking opt-out tool, which will allow you to stop some (or all) the companies on the list from using your personal information to target ads specific to you.

To stop this sort of online tracking completely, visit this website for more information. It will show you how you can use specific online tools like CCleaner to disable online tracking.

To learn more about online security, check out our “internet security” tag on our blog.