JUSTICE STEVENS delivered the opinion of the Court.At issue is the constitutionality of two statutory provisions enacted to protect minors from "indecent" and "patently offensive" communications on the Internet.While the ARPANET no longer exists, it provided an example for the development of a number of civilian networks that, eventually linking with each other, now enable tens of millions of people to communicate with one another and to access vast amounts of information from around the world.The Internet is "a unique and wholly new medium of worldwide human communication." The Internet has experienced "extraordinary growth." The number of "host" computers--those that store information and relay communications--increased from about 300 in 1981 to approximately 9,400,000 by the time of the trial in 1996.The Web is thus comparable, from the readers' viewpoint, to both a vast library including millions of readily available and indexed publications and a sprawling mall offering goods and services.From the publishers' point of view, it constitutes a vast platform from which to address and hear from a world-wide audience of millions of readers, viewers, researchers, and buyers.Taken together, these tools constitute a unique medium--known to its users as "cyberspace"--located in no particular geographical location but available to anyone, anywhere in the world, with access to the Internet.E-mail enables an individual to send an electronic message--generally akin to a note or letter--to another individual or to a group of addressees.
Newsgroups also serve groups of regular participants, but these postings may be read by others as well.These methods are constantly evolving and difficult to categorize precisely.But, as presently constituted, those most relevant to this case are electronic mail ("e-mail"), automatic mailing list services ("mail exploders," sometimes referred to as "listservs"), "newsgroups," "chat rooms," and the "World Wide Web." All of these methods can be used to transmit text; most can transmit sound, pictures, and moving video images.The District Court found that at any given time "tens of thousands of users are engaging in conversations on a huge range of subjects." It is "no exaggeration to conclude that the content on the Internet is as diverse as human thought." The best known category of communication over the Internet is the World Wide Web, which allows users to search for and retrieve information stored in remote computers, as well as, in some cases, to communicate back to designated sites.In concrete terms, the Web consists of a vast number of documents stored in different computers all over the world.