Newspapers and movie studios have reasonably good protections from government intervention and censorship. But as Steve Chapman explains, the Federal Communications Commission successfully has limited the First Amendment rights of television networks:
The First Amendment's guarantee of freedom of speech has complex implications, but it clearly means two things: The government cannot tell you what to say, and it cannot tell you what not to say. That is your own business, and if you conduct it in a way the government dislikes, the government can take a flying leap. Unless by "government" you mean the Federal Communications Commission. It operates on the assumption that in its special realm, the First Amendment is a nonbinding resolution.
In addition to the constitutional argument, he makes two excellent points. First, improving television quality (as defined by politicians) is not the business of government. Second, parents should decide what their kids see, not bureaucrats:
...parents who want to shield their kids from bad language on TV already have ample means to do so -- via channel blocking and V-chips that can be used to filter out programs with content they regard as inappropriate. The FCC says these methods are ineffective because parents don't use them. More likely, parents don't bother because they don't think the problem is serious enough to justify the effort to shield kids from words they've already heard on YouTube. To insert the federal government is not a way to strengthen the authority of parents but to circumvent it. ...The idea that we need the FCC to assure educational opportunities for children is nonsense on stilts. In the first place, there are plenty of channels, from PBS to the Discovery Channel, that offer nothing but educational programming. ...In the second place, any parents truly interested in exposing their children to intellectual stimulation are more likely to shut the TV off than turn it on. Even if more educational programming would be a good thing, what business is that of the government? More G-rated films would be a good thing, too, but we don't force movie studios to produce them. ...Today, most viewers no longer distinguish between cable and broadcast programs. So having different rules for each makes about as much sense as having different regulations for odd- and even-numbered channels.