> Adult pornography on the internet is actually illegal in the US
Could you provide a citation or evidence of this, please? There have certainly been attempts to regulate it, with mixed results. But even casual research leads very quickly to the Supreme Court case that struck down porongraphy provisions of the Communications Decency Act. ( http://en.wikipedia.org/wiki/R...) And even that unconstitutional law attempted to restrict pornography to minors, not pornography as a whole.
There was a particularly memorable quote in the Supreme Court case, one to keep in mind when filtering Internet traffic. That includes this, and the recent blocking of ISIS traffic on twitter.
> Through the use of chat rooms, any person with a phone line can become a town crier with a voice that resonates farther than it could from any soapbox. Through the use of Web pages, mail exploders, and newsgroups, the same individual can become a pamphleteer.