To address privacy concerns regarding Facebook and similar I use a plugin that prevents the transfer of casual servers to third parties. The technique was developed by heise.de and was implemented as a wordpress plugin by Helmut-Peter Pfeufer.
The concept is simple, instead of the usual buttons for Facebook, Twitter etc. a simple image is shown that looks similar to the original button, but grayed out. Upon click on the button the “real” button is loaded and replaces the image. This is the first time data about the visitor is transferred to the corresponding site. A second click on the button sends the recommendation.
The user has the option to keep the buttons for the sites always enabled, so they will act as normal buttons.