Like every individual, hollywood actors too use Social networks. One popular example is Paula Abdul informing her decision of leaving American Idol via a tweet. I think you got the point. Through these social networking sites, various movie related items have leaked which has made a bad impact on Movie studios. Well Movie Studios have decided enough is enough. They are introducing new contracts that will restrict and forbid actors and other related stakeholders from leaking movie related info on the social network.
DreamWorks and Disney are the first studios who will be enforcing restriction on tweeting via Twitter. Cameron Diaz and Mike Myers will be the first one to be affected by this restriction in their upcoming Shrek sequel. Celebrities have been big fans of social media because it allows them to broadcast their thoughts directly without being filtered by journalists. This decision by Movie studios can be seen as a control parameter.