The authority has a central role in the reception of scientific media products and, more generally, in the position of science in society. In the world of the new media, this role is even more underlined, because content is built by the community, by the users. Here the credibility of science can be defended not by rules or power, but in two other ways.
On one hand, science has to take pride in its tradition and ambition to pursue truth. I know this runs against the postmodern, relativist and social constructivist mainstream of humanities and politics, but it characterizes the real working of science. Of course, the power of the media and politics (like it happened in the era of Nazism or Maoism) can force science to surrender the classic Humboldt–Vannevar Bush model of the autonomy of science. I am sure that science has theoretical and practical arguments to use in this fight.
On the other hand, the prestigious science and scientists have to become competitive in the new media. That means they have to communicate with laypeople and give answers to their reasonable questions, and have to be open for this discourse. In short, we need media-able science, not medialized science.