WASHINGTON, D.C. — The Simon Wiesenthal Center in Los Angeles has created an uproar on the Internet with its recent recommendations on curbing the rise of hate groups in cyberspace.

The center called upon Internet providers around the country this week to adopt an ethics code stressing their obligation to deny platforms to groups promoting racism, violence or anti-democratic activity.

Censorship is not the issue, according to Rabbi Abraham Cooper, associate dean of the center and its chief cyberspace activist.

"We recognize that the Internet is an ever-expanding mode of communication," he said. "According to some recent statistics, four percent of all Americans are surfing the net."

The attractiveness of the new medium — "all the bells and whistles," Cooper said — has combined with the unfiltered nature of the information distributed through online communication to boost fringe groups that have never before had direct access to mass media.

He insisted that the group is not calling for added government regulation or new laws. Internet providers themselves, he said, should make fundamental decisions about who should have access to their services, just as broadcasters make judgments about who can purchase air time.

Added Cooper: "All we're saying to the providers is this: have you considered what are the rules of engagement? Where will you draw the line?

"We are not asking for constraints. But if somebody comes to you with this kind of material, what will your response be? Providers need to start discussing these issues."

The Wiesenthal Center has singled out 70 sites on the Internet's World Wide Web for their racism, advocacy of violence or homophobia.

"The issue here isn't banning ideas," he said. "That never works. The real question is how do you marginalize the lunatic fringe in our society?

"The Internet, for the first time, offers these groups a cheap, incredibly effective medium for spreading their message. Providers need to start thinking about these issues."

But that call for self-examination and voluntary regulation provoked a furor on the net.

The American Civil Liberties Union, in an action alert posted on the Internet, warned that the Wiesenthal Center was waging "an all-out war to deny such groups of their equivalent free speech rights…It is particularly troublesome that an organization like the Wiesenthal Center that is dedicated to promoting tolerance would seek to erode the liberty most necessary for a free and tolerant society — free speech."

The ACLU doesn't deny the existence of hateful speech on the net. But the online racists and anti-Semites, they maintain, are balanced by the Internet sites developed expressly to counter such propaganda.

The Wiesenthal Center position also worries David H. Rothman, a leading Internet observer and author of "Networld!: What People Are Really Doing on the Internet — and What It Means to You."

"We don't need repression — `voluntary' or not," he said.

"Besides, I want to know what Nazis and near-Nazis are up to, and the Internet is a handy way to find out. If nothing else, Internet sites are time-eaters; better that the nuts devote themselves to computers than to rifle practice."