One point from the article I found most interesting: > Pages that contain Facebook "like" buttons enable Facebook to track visitors to those pages. Facebook tracks Internet users that see "like" buttons, even users who never visited facebook.com and never click on those buttons. > The ACLU has a way of enabling users to click a Facebook "like" button, which avoids this problem. Its pages have a link called "like us o…
Note that Facebook doesn't like having the loading or function of their like button altered (they want the third-party page loads for targetting)[3]
Note also that some of the share button widgets that aggregate the different social networks into one widget (like AddThis and ShareThis) pitch themselves are more privacy friendly but they are much worse - they will track and target you and sell your data to every network they can.
They also use (or used) evercookie techniques such as canvas fingerprinting or cache-based fingerprinting for persistent and privacy-setting resistant tracking[4].
[0] https://github.com/JonathanMH/privacy-friendly-facebook
[1] http://www.h-online.com/features/Two-clicks-for-more-privacy...
[2] https://github.com/panzi/SocialSharePrivacy
[3] http://translate.google.com/translate?sl=de&tl=en&js=n&prev=...
[4] https://go-to-hellman.blogspot.com.au/2014/08/libraries-are-...