NEW YORK -- Amateur Action, a computer bulletin board that advertises itself as "the nastiest place on Earth!," was still open for business yesterday despite the conviction of its owners last year on charges of transmitting obscene material over computer networks.
The only change appears to be a warning that greets all callers: "Amateur Action BBS is for the private use of the citizens of the United States! Use by law enforcement agents, postal inspectors, and informants is prohibited!"
Business appears to be good: A reporter was told he was "caller No. 1,083,677" just before he was offered a menu of choices that included "Oral Sex," "Bestiality," "Nude Celebrities" and "Lolita Schoolgirls."
Sexually explicit fiction and digitized photographs of naked people are common on the nation's rapidly growing computer networks, as are forums for discussing sexual fantasies.
And computer experts and lawyers who specialize in cyberspace issues say a proposal in the Senate to bar such material from the nation's information networks is impractical, unenforceable and perhaps unconstitutional.
"My major concern is to make the new Internet and information superhighway as safe as possible for kids to travel," said Sen. Jim Exon in an interview yesterday. The Nebraska Democrat is the author of the proposed Communications Decency Act of 1995.
The proposal, which cleared the Senate Commerce Committee on Thursday without dissent, would impose fines of as much as $100,000 and two-year prison terms on anyone who knowingly transmits any "obscene, lewd, lascivious, filthy, or indecent" communications on the nation's telecommunications networks.
The law would apply to telephone systems, cable and broadcast TV systems, and public and private computer networks, including the global Internet.
Similar laws have been proposed in several states, reflecting a growing national concern over use of a new communications medium that now reaches millions of homes in the United States.
"The potential danger here is that material that most rational and reasonable people would interpret as pornography and smut is falling into the hands of minors," Mr. Exon said.
Proposals for restrictions have been met with incredulity and outrage by Internet users, legal experts and civil libertarians, who contend that efforts to halt the flow of information in cyberspace -- where, in effect, every computer is a bookstore and a printing press -- are futile on both technical and legal grounds.
There are more than 70,000 private computer bulletin board systems in the United States and even more private business networks.
Private commercial computer networks, including America Online, Prodigy Services and CompuServe, have nearly 6 million subscribers. Many of them are connected to the Internet, the biggest network of all.
The Internet is a vast collection of mainly private computer networks, connecting millions of users in about 150 countries. More than half the users are outside the United States.
The overwhelming bulk of material on computer networks is not sexual, and the fastest-growing segments of Internet traffic are related to the transmission of business information and computer software.
So attempting to filter out sex-related material from the torrent of digital bits passing through tens of thousands of computer networks "is like shooting an ICBM at a gnat," said David Banisar, a lawyer for the Electronic Privacy Information Center, a lobbying group in Washington.
Dan L. Burk, visiting assistant professor of law at George Mason University, in Fairfax, Va., noted that courts have required attempts to protect minors from objectionable information, as in telephone "dial-a-porn," to use the "least restrictive means" to accomplish the goal.
A comprehensive ban on such material on computer networks, Mr. Burk said, could restrict material that courts have ruled legal to disseminate to adults through more conventional outlets.
"If the burden becomes too high for protected adult speech, then the statute clearly is not going to pass muster" in federal courts, he said.
Internet experts note that while information flows freely over the Internet, the medium differs significantly from broadcast media such as television or radio.
With few exceptions, users have to actively seek sex-related material, which can be difficult to find among the vast resources of the global network. In the case of some photo files, the user typically must use more than casual technical skills to assemble the images for viewing.
Because of the international nature of the Internet, creators of sexually explicit material can quickly set up operations overseas or transfer their material to foreign computer networks. Americans participating in sex-related discussions on their computers can just as easily route their messages through so-called anonymous remailers who hide their identities.
Given the likelihood that sex-related materials will continue to proliferate in cyberspace, there is a growing interest in finding a way to filter objectionable material from the torrent of information.
"Anybody who knows anything technical about the Internet would understand that this is ridiculous," said Ron Newman, a computer programmer in Somerville, Mass., who until recently worked at the Media Labs at the Massachusetts Institute of Technology.
Some schools and companies are taking initial steps to restrict access to portions of the Internet where sexual content is common, especially the global network Usenet.
Typically reached through the Internet, Usenet consists of more than 10,000 discussion groups. Of the 20 most popular Usenet forums, half are on sex-related topics.
Some universities, including Carnegie-Mellon in Pittsburgh, have filtered out access to sex-related Usenet groups, ostensibly to preserve scarce computing resources for more academic topics.
Siecom Inc., an Internet service provider in Grand Rapids, Mich., provides 20 elementary and secondary schools with restricted, one-way access to Usenet discussion groups. Besides eliminating questionable news groups, Siecom also gives schools the option of scanning all incoming and outgoing student electronic mail for objectionable words. A school can designate the words it will not allow.
"We really had no idea that the level of interest in our service would be so high," said Rob Oates, president and general manager of Siecom.
Commercial on-line services that connect to the Internet, including Prodigy and America Online, already include simple software tools that can be used by parents or teachers to restrict access to some of the dicier areas of the network.
"We do not believe our role should be as surrogate parents for anybody," said Brian R. Ek, a spokesman for Prodigy, a service based in White Plains, N.Y., that has an estimated 2 million users. "We tell you about the good, the bad, and the ugly on the other side of the curtain and let you make the choice."
Prodigy's software requires a household's main account holder, who must have presented a valid credit card number and thus is presumed to be an adult, to activate access to individual Usenet, chat and bulletin board areas for other members of the household. Without such action, the areas are blocked.
America Online, the country's fastest-growing commercial service, simply hides the names of sex-related news groups from a menu of Usenet options. To gain access to a sex-related board, the user must type the exact name of the news group.
Many Internet users have suggested that controls by parents or teachers are superior to controls by the government.
"Governmental control sufficient to shield children from any chance of exposure to indecent material would have to limit it to the point that adults couldn't access it either," said Mr. Burk, the law professor, "reducing adult speech, as the Supreme Court says, to the level appropriate to a child."