When a federal judge refused to stop the gadfly operator of an Internet site from publishing confidential Ford Motor Co. documents last week, she described the dispute over trade secrets as a clash between free speech and commercial innovation.

"In this case, the battle is won by the First Amendment," Detroit Judge Nancy G. Edmunds concluded, allowing the operator of the blueovalnews.com site to continue posting the confidential documents he said he had received anonymously.

Legal experts touted Edmunds's opinion as a major precedent for free speech in cyberspace. But it is only the latest in an emerging pattern of decisions enhancing expression in the communications revolution that is the Web.

Equally striking, the ruling in the Ford case illustrates how even though the Internet has transformed how people go about their lives, it has not transformed the law. Unlike the rise of broadcast television and other media over the decades, in which new technologies generated new bodies of law and extensive government regulation, the Internet is being treated much like newspapers or books, with judges emphasizing the primacy of the First Amendment.

"The medium is different. But judges are ruling that it's the message, not the medium, that drives the result of a case," said Robert M. O'Neil, director of the Thomas Jefferson Center for the Protection of Free Expression in Charlottesville.

While the law is still developing and some rulings restricting speech on the Internet have been handed down, lower courts are generally extending the path cut by the Supreme Court when it first went into cyberspace, in 1997, to overturn a federal prohibition on "indecent" materials. Although the high court described the Web as a "unique and wholly new medium," in the end it concluded that its functions are not so different from the kind of communications that led to the First Amendment in the first place: "[A]ny person with a phone line can become a town crier with a voice that resonates farther than it could from any soapbox," Justice John Paul Stevens wrote. Through the technologies of online publishing, "the same individual can become a pamphleteer."

Such reasoning appears to be why, despite the staggering changes produced by the Internet, courts have not created a distinct body of law to deal with cyberspace.

Last November, when federal judge Leonie M. Brinkema ruled that the Loudoun County, Va., library could not install "blocking" software on its Web-connected computers to stop patrons from using sites deemed pornographic or harmful to children, Brinkema relied on established rules for free speech and public forums. The judge, herself a former librarian, said that while the library is not obliged to provide Internet access, once it does, it cannot restrict adult use without a compelling governmental interest.

Similarly, in May, when a 9th U.S. Circuit Court of Appeals panel ruled 2 to 1 against the Clinton administration's restrictions on posting encryption codes on the Internet, Judge Betty B. Fletcher relied on First Amendment precedents protecting newspapers from restraints on publication. Encryption software scrambles communications to protect privacy, and federal officials fear the technology will be used to conceal criminal activity.

But Fletcher, siding with an Illinois math professor who wanted to post his encryption formula, dubbed "Snuffle," rejected the government's view that a "source code" is different from traditional forms of expression because it can control a computer's operation. "In this increasingly electronic age, we are all required in our everyday lives to rely on modern technology to communicate with one another," Fletcher wrote, noting the accompanying need to keep those e-mail, cell phone and Internet businesses private. "Government efforts to control encryption thus may well implicate not only the First Amendment rights of cryptographers intent on pushing the boundaries of their science, but also the constitutional rights of each of us as potential recipients of encryption's bounty."

Still, there is not unanimity on the question of encryption. Dissenting from Fletcher's opinion in the Ninth Circuit ruling, Judge Thomas G. Nelson said the First Amendment should not apply. An encryption code, he said, "is inherently a functional device." And in a similar case in Cleveland a district court judge sided with the government against another professor who wished to post several encryption programs on his Web site. That case is now on appeal and could ultimately lead to a showdown on the issue at the Supreme Court.

One of the most publicized court decisions limiting free speech on a Web site came in February when an Oregon jury produced a $107 million verdict against antiabortion activists who used a Web site called the "Nuremberg Files" to target physicians who ran abortion clinics. But that case appeared to limit only the most extreme forms of speech; the judge told the jury that to find against the Web site it had to decide that the statements would be interpreted as a serious expression of an intention "to bodily harm or assault." The case is still on appeal.

Another contended area of cyberspace law that has run through its appeals is this question of whether service providers can be held liable for defamatory messages that third parties post on their systems. The benchmark case began when Kenneth Zeran of Seattle became the victim of a despicable practical joke. A week after the 1995 bombing of the federal building in Oklahoma City, someone posted a message on an America Online bulletin board advertising "naughty" souvenir T-shirts of the bombing for sale by Zeran.

Zeran was inundated with angry calls and death threats, particularly from the Oklahoma City area, where a radio station announcer mentioned the offensive T-shirts on the air. Zeran sued AOL, maintaining that it had an obligation to remove the defamatory posting and tell subscribers it was false.

But the U.S. Court of Appeals for the 4th Circuit ruled that service providers are not responsible for postings by a third party. It relied on a provision of federal law that the court said was intended "to maintain the robust nature of Internet communication and, accordingly, to keep government interference in the medium to a minimum."

Last year, the Supreme Court rejected Zeran's appeal and let the 4th Circuit ruling stand. That 4th Circuit decision also provided a basis for a district court's dismissal of White House adviser Sidney Blumenthal's libel suit against AOL earlier, stemming from statements posted on AOL by electronic gossip journalist Matt Drudge.

"There's a real temptation to look at the excesses of any medium, the nastiness and the hate." said Jeremy D. Mishkin, a Philadelphia lawyer who specializes in intellectual property law. "But, so far, in the court decisions we've seen, freedom of speech is still the default setting."