During Mark Zuckerberg’s Congressional testimony last week, the Facebook CEO said that the company collects data of people who have not signed up for the site “for security purposes.” And it raised some eyebrows about how Facebook collects data when users aren’t active on the site.
It seems Facebook wants to clarify what exactly its CEO meant. The social media giant published a blog post on Monday that seeks to explain how the site collects your data—particularly when you’re not logged into Facebook.
David Baser, the product management director at Facebook, writes that there are four instances in which Facebook receives your data from third-party websites and apps:
- Social plugins: including Facebook’s like and share buttons, allowing you to share content on Facebook
- Facebook login: logging into a third-party site or app via your Facebook account
- Facebook analytics: allows websites and apps to understand how people use their services
- Facebook ads and measurement tools: website and apps run their ads on Facebook or vice versa
Baser notes that these tools are used by websites and apps to “make their content and ads more engaging and relevant.”
When third-parties engage such Facebook services, Facebook receives the corresponding information—even if you’re not currently logged in to Facebook or do not have an account.
Baser says these techniques aren’t employed by Facebook alone; a number of online services similarly receive user data. Twitter, Pinterest, LinkedIn all have like and share buttons. Google offers an analytics service. And Amazon, Google, and Twitter all have login features. All of these websites also offer advertising services.
Baser says that “most websites and apps” send information to “multiple companies each time you visit them.” In the case of Facebook, the information it receives includes the name of the website or app, your IP address, your browser, what operating system you’re using, and whether you’ve previously visited the site. That data can then be matched with a Facebook profile if you have one. But, significantly, Facebook told CNNMoney that the site does not have “shadow profiles” for users who do not have Facebook accounts.