With the advent of the Internet, principally the World Wide Wide, the belief that freedom of speech without limit is a constitution right. That of course is not so. The first amendment bars only government from abridging freedom of speech.
It is perfectly legal for internet providers, search engine providers, social media sites, news and opinion sites, businesses etc to do content filtering. In fact, most do to some extent now. Prior to the Internet, newspapers, TV, and radio filtered content. Remember the New York Times slogan, "All the news that is fit to print". These organizations filtered content because the public demanded. it. And this is how we should filter content today, in response to public demand. This begins with educating public and establishing a means for the public to request certain types of content be blocked. This won't stop all such content, nor should it. However it can serve as a limiting factor in the propagandizing of the country with misleading dangerous, and false information.