What responsibilities does the news media have on society?

The media used to be known as the 4th estate during olden times as they are so influential/powerful/large that they deserved to be known as an "estate" on their own (1st estate = royalties; 2nd estate = clergymen; 3rd estate = common men)

The mass media has a watchdog role, meaning they are the eyes of the common people. They are responsible for keeping tabs on important figures (such as governing bodies, celebrities) so that citizens will be able to get a holistic picture when decisions have to be made (EG. elections)

However, sometimes the media might withhold information from the public as they have been instructed by the governing bodies to keep mum about certain news until a certain date. One example would be the escape of the terrorist Mas Selamat from Singapore's Whitley Road detention centre. Other examples include the death of a president, which might affect social/political stability.