Freedom of Speech, freedom of expression, both oral and written, from governmental prior restraint, except as such expression constitutes libel, slander, obscenity, sedition, or criminal conduct such as bribery, perjury, or incitement to riot. In the U.S., this freedom is protected by the 1st Amendment of the Constitution. At the core of 1st Amendment concerns is the protection of expression that is critical of government policies.
Also, if the people of the government think censoring American sites from having "vulgar" material on them, what happens when this child goes to a site that either has a nice sounding name that they don't think to block because it does not sound incriminating. If people don't want their children to be on obscene sites then they could put a block on that site at their own computers and make it for that child's screen name instead of the entire Internet. If there are people old enough to visit these sites they should not be blocked from everyone. But it may also be a good thing for them to censor the Internet for reasons of there are some pretty nasty ones out there and they may not have any incriminating content on them, but they are pointless and destructive to other peoples computers. There are some sites that have viruses on them and other people enter not knowing and that should definitely come to an end. Although these sites are dumb, the more you destroy the more sites just like it are made.
The porno sites and other adult content sites should not be blocked. I say this because if they are going to look for it there is no way you can hide it from the children that have access to the Internet. Also there is no way of proving how old you really are on a computer, so there is no way a child can be caught on the site he/she is not supposed to be on. .
If Congress starts to limit the ability of the Internet it would be against everything that it was made for, and at the same time those people probably also use the Internet for those purposes and are just agreeing with the higher people on the latter so they don't have to argue over the subject.