Do social networks harm work?

On Habré more than once they wrote about the dangers and benefits of social networks for work. Such articles generated a lot of controversy in the comments.
Nineteen-year-old Jonathan P. from West Virginia apparently missed Barack Obama’s appeal about Facebook’s harm to his career , and, as a result, it completely collapsed at the very beginning.

Jonathan P. planned everything perfectly - in the afternoon, when no one was home, through the bedroom window he made his way to his victim's apartment and took possession of two rings with diamonds. But then his computer turned on his attention, and Jonathan decided to quickly see which of his friends are online on Facebook. It was then that the beginning bosom made his fatal mistake - he forgot to log out.

After the owner returned home and discovered the loss, she saw the open profile page of Jonathan on Facebook-e. It was not difficult for the police to find out the name, hobbies and friends, and then the address of the criminal who is currently sitting in the detention center - if convicted, he faces up to ten years in prison.

Via Spiegel via The Journal