Facebook: Yep, we track non-users -- but everyone else is doing it, so why shouldn't we?

In a blog post addressing some of the questions Mark Zuckerberg failed to properly answer in front of Congress, Facebook has admitted that it tracks both users and non-users as they use the web. This is something the social network has historically denied.

Facebook's product management director, David Baser, conceded that "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." Not happy to make this concession without pointing fingers, he then goes on to point out that other companies such as Twitter, Pinterest and LinkedIn behave similarly.

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If you were hoping for detail from Facebook, you're out of luck. Baser -- while trying to give the illusion of transparency -- does little more than point out that other companies are collecting data about non-users in the same way as Facebook. He says that sites that use social plugins (Like and Share buttons), Facebook Login, Facebook Analytics, or Facebook ads and measurement tools record certain information about people.

He explains:

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. This is because other apps and sites don’t know who is using Facebook.

Many companies offer these types of services and, like Facebook, they also get information from the apps and sites that use them. 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.

Baser then enters full-on patronizing mode, explaining how and why sites with integrated Like and Share buttons send us information to make their content and ads better. (It's for your own good, remember).

To understand more about how this happens, it helps to know how most websites and apps work. I’ll use websites as an example, but this generally applies to apps, too.

When you visit a website, your browser (for example Chrome, Safari or Firefox) sends a request to the site's server. The browser shares your IP address so the website knows where on the internet to send the site content. The website also gets information about the browser and operating system (for example Android or Windows) you're using because not all browsers and devices support the same features. It also gets cookies, which are identifiers that websites use to know if you’ve visited before. This can help with things like saving items in your shopping cart.

A website typically sends two things back to your browser: first, content from that site; and second, instructions for the browser to send your request to the other companies providing content or services on the site. So when a website uses one of our services, your browser sends the same kinds of information to Facebook as the website receives.

He adds:

We also get information about which website or app you're using, which is necessary to know when to provide our tools.

Baser goes on to detail some of the data stored about users and non-users: IP address, browser/operating system information, the address of the website or app in use, cookies, device identifiers, country information, and more. He says: "Cookies and device identifiers help us determine whether the person uses Facebook. If they don't, we can show an ad encouraging them to sign up for Facebook. If they do, we’ll show them ads from the same advertisers that are targeting them on Facebook. We can also use the fact that they visited a site or app to show them an ad from that business -- or a similar one -- back on Facebook."

He does not, however, go as far as owning up to the existence of shadow profiles that could be used to not only follow non-users around the web, but build up detailed profiles about them.

He signs off by saying:

Whether it’s information from apps and websites, or information you share with other people on Facebook, we want to put you in control -- and be transparent about what information Facebook has and how it is used. We'll keep working to make that easier.

This is said without reference to the non-Facebook users who have no control over data collection -- unless they opt to manually block all of the site's cookies, that is.

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