Depends on the work enviroment
I definitely think that it depends on the work environment. If you have a job that doesn't require you to be up to date and current with events and news then I would say social media should be limited to the lunchbreak. If you live and work in technology you know that staying up with the most current trends and information is a critical part of the job. I remember my boss saying to me, "you have to consider the place we work" social media is an important way to stay connected.