Facebook Explains How It Tracks You Even When You are Not Logged In

Following Facebook CEO Mark Zuckerberg's testimony to the US Congress, the company has shared a blog post by Product Management Director David Baser where it talks about the different ways in which it tracks users on other websites and apps. Although much of this has been reported on before, until now, Facebook has not commented in detail on its activities. However, with the post on Monday, the company revealed that there are lots of different methods it uses to track users, even when they're not logged into Facebook.
The blog post highlights the four main tools that Facebook has at its disposal to track you with even if you're visiting other websites. The most obvious one is of course, using Facebook to log into a website. Both Facebook and Google can be used to log into various websites, and a lot of people choose to do this because it's easier than creating a new password for every site.
However, once you've done this, Facebook is able to track you on the site that you're visiting. But even without this, Facebook has a number of different tools that it can use even when you're not on the social network, in order to track you. For instance, if you see 'Like' and 'Share' buttons on an app or site, that also gives Facebook information about you.
But apart from these kinds of visible indicators, Facebook also offers ads and analytics tools to websites and apps, and even in these cases, Facebook can track you, even if you possibly don’t see any Facebook branding or widgets on the website. As Facebook noted, "when you visit a site or app that uses our services, we receive information even if you’re logged out or don’t have a Facebook account." The post also gives us a look at the kind of data that Facebook is able to collect when you visit a website, or launch an app, which uses one of its services.
To start with, your IP address (think of it as your address on the Internet), your browser, and your operating system are all shared with Facebook. This happens for every site that you visit, or app that you use, which uses any of Facebook's services, from the more visible ones, to the ones that are running under the hood which most users will never know about.
Of course, Facebook is quick to point out that it's not the only one that does this kind of tracking either. Facebook points out, correctly, that when you visit most sites, your data is actually being mined by several companies, every time. Facebook points out: Twitter, Pinterest and LinkedIn all have similar Like and Share buttons to help people share things on their services. Google has a popular analytics service. And Amazon, Google and Twitter all offer login features.
These companies — and many others — also offer advertising services. In fact, most websites and apps send the same information to multiple companies each time you visit them. So once Facebook - and these other platforms - have your data, how are they using it? Facebook's post explains that it's used to provide Facebook's services - such as the social plugins, or ads - and also to improve security on Facebook, and improving its products and services.
The post also stresses that Facebook doesn't sell people's data, and that there are user controls that can let you opt out of such targeting advertising on or off Facebook. Of course, there's a question mark that has to come in there, because what Facebook does sell is the ability to accurately target users based on the profiles that have been built up to anyone who wants to reach them.