When it comes to tracking, Facebook is another company that you have to be wary of.
The omnipresence of Facebook widgets such as ‘Like’ buttons provides Facebook with incredible amounts of information about your online activity. Every time you visit a site with a ‘Like’ button, Facebook can know about it. And Facebook has not been as forthcoming about its tracking activity as Google, and it doesn’t provide the same means of deleting and reviewing your records. Thankfully, the browser privacy add-ons like Disconnect and Ghostery are also effective against Facebook widgets. More on curtailing Facebook on page 64.