Free Speech and the Internet

As guardians of free speech and long time defenders of free speech (which includes checking out materials) librarians need to figure out a way to deal with the internet within libraries and protecting free speech still. This goes for searches, downloads and other materials. Also, with sites like Twitter and Facebook, that do not guarantee free speech, do they pose issues or threats that need to be dealt with. Whereas some US corporations on the internet say they protect free speech on the web, others do not. Is this an area of programming that would be good to do. Is it necessary to know what sites provide a "free speech" platform and what do not.