I heard a quote the other day which is, I think, an old adage "free speech does not mean you are allowed to yell 'fire' in a crowded theatre"

To that end, I actually think that a lot of Brietbart's content is akin to shouting 'fire' in a crowded theatre. Consider for example the "black crime" segment- while the crimes may be true, the method of presentation foments racial prejudice. Consider the "bowling green massacre". Consider the following example from a researcher named yochai benkler:

BENKLER: A simple example, the second most Facebook shared story on Breitbart gets shared with the links "Jerry Brown Signs Bill Allowing Illegal Immigrants To Vote."

INSKEEP: Jerry Brown, the governor of California.

BENKLER: The governor of California signs a bill allowing illegal immigrants to vote. Then you go to the site. And you look at the headline. And it says could let illegal immigrants vote. Then you actually read the story. He signed a motor voter law.

INSKEEP: A true story about potential confusion over who has the proper ID to vote is recast as a conspiracy for Democrats to keep power.

BENKLER: Bits and pieces are true. The overall is fundamentally misleading and misdirecting and feeds into this core paranoia over voter fraud and illegal immigration, which are central themes in the Breitbart sphere throughout the election.

The media in a free and open society have fundamental critical rights. But in addition, they must also bear responsibility. One of those responsibilities in my opinion, is that they must not lie to, or fundamentally mislead the public

Hate speech should not be free speech (and in much of the world, is not) additionally, false speech by media should not be free speech, and in some of the western world is regulated (Canada and the U.K. both have regulations around truth & balance in media)