It's all I can do to convince people they can't use strict constuctionist arguments that say the original intent of the First Amendment was only to protect political speech, and then turn around and argue that since porn isn't protected we can use living document "New Deal" Commerce Clause legislation to regulate it.
The government, like a private corporation, has the right to restrict material conveyed on publicly owned media. Not all of it, but some parts of the internet are government owned.