Today I learned that, Facebook (which is notorious for violating users privacy) along with other social networks tracks your every move while you are on the web. Whenever you log-in your Facebook account or visit the website, they place a cookie in your web browser data that stays in your computer even after you logout your account. The cookie works like a malware and sends back data (web history, visits) and other statistics to Facebook.
Morever, the Facebook Share/Like button on the websites/blogss does the same. Not only Facebook is doing it, but other big social networks such as, Twitter, Facebook, LinkedIn are reported doing it. In order to protect your privacy and important stuff. It’s better to clear cookies/logout your social accounts while doing work so they don’t track you. There are also services available, DotNotTrackMe that prevents cookies from tracking your web visits.