The only thing that has changed is that the tools are more sophisticated. Fortunately, quite a large variety of tools is available to enable parents and teachers to similarly limit pornography in the classroom. It is not technologically or logistically possible to stop adult content from being published on the Internet. Much adult content already comes from overseas. Legal bans on domestic publishing will just accelerate the movement of pornographers overseas.
Any computer can publish on the Internet.
Schemes to disconnect or block individual computers can be defeated by simply changing the address of the computer or copying the files to another server. Data travels in random paths around the global Internet. Preventing prohibited content from entering the U.S. is as futile as a ban on Canadian thunderclouds. The Internet is like a giant funnel. Everything is being poured into it from all over the world.