After a report from advocacy group, Privacy International, revealed that Facebook routinely tracks the web-browsing activities of users and non-users alike, the social media company has accepted that it does track non-users and logged-out users, but claimed that such practices are "common" for many companies, and is useful for both users and the companies involved.
According to The Independent, Facebook said, "This information is important for helping developers understand how to improve their apps and for helping people receive relevant advertising in a privacy-protective way. We do this in a transparent manner by explaining the practice through our Data Policy and Cookies Policy, and by using Google's advertising identifier, which can be controlled centrally by people using their device settings".