Freedom of speech means you can say what you want (short of libel or slander) and the government is prohibited by the First Amendment from stopping you. It doesn't prohibit a private entity from throwing you off it's privately owned broadcast facilities, or from you, for instance, from throwing someone out of your house for what they say. It also means that there are consequences - people angry that Savage has been fired from MSNBC are free to boycot MSNBC, and all of their corporate sponsors.