Under the provisions of the First Amendment, the media—including television, radio, newspapers, magazines and the Internet—are free to distribute a wide range of news, facts, opinions, and pictures, even if those sources are critical of the government itself.
The government can, however, subject the media to the same restrictions on free speech as the rest of society: a limit or ban on libel, obscenities, fighting words, and words that present a clear and present danger of causing violence. In addition, where the government regulates the broadcast medium, such as the television or radio airwaves, it can regulate some ownership interests and content distributed as a condition of ownership.
The United States Constitution, What It Says, What It Means, A Hip Pocket Guide