This is an ever increasingly important question. Mass media by definition is information (the news) for the people. Under this definition institutions such as the news companies and other information companies are included: The New York Times, The Wall Street Journal, Internet based News such as CNN.com, and TV News programs. These mass media institutions have a responsibility to report what is taking place in a responsible way. This means that they must be honest, filled with integrity, and decide what is best for the public. These tasks are inherently difficult to do, because no one can report on everything. All news is selective and from a certain point of view or slant. Hence, companies should above all let their biases be known and put themselves under the highest standards of ethics.
One more point can be made. Due to the rise of the internet, more information is being disseminated through websites and blogs. In addition, with the rise of twitter and facebook, things may change again. If these companies grow, ethical standards should be put in place.