Australian technologist Nik Cubrilovic: ‘Logging out of Facebook is not enough’ Even after you are logged out, Facebook is able to track your browser’s page every time you visit a website. ‘The only solution to Facebook not knowing who you are is to delete all Facebook cookies,’ he said. After explaining the cookies behavior he also suggested a way to fix the tracking problem: ‘The. only solution is to. delete all. Facebook cookies’ He said: ‘With my browser logged out of. Facebook, whenever I visit any page with a Facebook like button, or share button, the information, including my account ID is still being sent to Facebook’
Source: https://thehackernews.com/2011/09/facebook-track-your-cookies-even-after.html