Media, a plural noun; medium is the singular. A medium is a system of mass communication: The medium of television is a prominent component of the mass media.
Every day we hear and read statements like "The media is irresponsible," "The media has a hidden agenda." In those sentences, "media" should be followed by "are" and "have."
There are some who prefer and defend "the media is" and "the media has." To them, the various means of mass communication—newspapers, radio, TV, magazines, blogs, etc.—make up one "media."
The United States is where I live is correct, even though "States" is plural, so why not "the media is," even though media is plural? Nice try, but no sale.
Writers should insist on the media are. It's important that people think of the media as many voices, opinions, and perspectives rather than one monolithic entity.