As the Internet has its principle origins in the academic world, it has a tradition of freedom of information with little or no censorship . The academic world thrives on the free exchange of ideas and information, and would be stiffled without it. With the Internet now available to anyone with a computer and a phone line, there is increasing concern about the kind of information that can be found, and some are pressuring for some kind of censorship. The media of course has got in on the act, with claims that the Internet is riddled with huge quantities of hard core porn, and a child wouldn't be able to use the net without discovering it accidentally at almost every turn.
There is of course material on the Internet that children shouldn't see, and material that most adults probably don't want to see. It includes far-right propaganda, activist literature (such as extracts from the Anarchist's Cookbook, and bomb-making instructions), recreational drug information, and pornography (most of which is of the ``soft'' variety, although there probably is some of the ``hard'' variety, including stuff to please paeodoephilliacs). It certainly isn't that common though, and you are unlikely to come across it by accident -- especially the more disgusting stuff.
There are reasons for allowing dodgy material on the Internet, as banning it would simply drive it underground and whilst it is visible, it is possible to keep an eye on what is happening. Where I work, academics track the behaviour, and attitudes of far-right groups by checking out their propaganda, and I wouldn't have realised that there were people stupid enough to deny the Holocaust if I hadn't encountered their ignorant trash. If the Internet is censored, there is the problem of just what to censor -- the Internet is international, and standards for acceptable material vary. Do we want an Internet where the only material allowed, is the blandest trash allowed by the most restrictive regimes, or the kind of material that is suitable for young children to view ?
Besides which there are software products designed to work on your machine that will block access to known adult content sites. Some will even block access to sites that contain words in a censored list. Although not perfect1.7, they are certainly suitable for preventing the majority of teenagers from looking at sites that their parents think that they should not. Of course, there are a small number who will work out how to get around the restrictions but this is likely to be smaller than most people think.
Certain organisations, and governments are already trying to censor the Internet. The Singapore government managed to get an ``anonymous re-mailer'' service closed down in Finland, which a dissident was using to stay anonymous whilst he was criticising them. They didn't care that such ``anonymous re-mailer'' services are used by people contacting the Samaritans online. The Church of Scientology is using legal harrassement to keep its critics silenced and off the Internet.
Internet service providers are also under attack. The German government is suing CompuServe for ``publishing'' obscene material (CompuServe didn't restrict access to certain Netnews news groups), and a Uk ISP stopped carrying some Netnews groups after being warned by the police. This is especially puzzling when common sense indicates that ISP's qualify for ``common carrier'' status in the same way that postal delivery companies do -- when a letter bomb is delivered to your house, it is the person who sent it who is responsible and not the postman.