Is there a constitutional right to communicate with others anonymously? Though the United States has a distinguished tradition of anonymous (and pseudonymous) publication -- the Federalist Papers, written by Alexander Hamilton and James Madison but published under the pseudonym Publius being only the most historically significant example -- the Supreme Court has never completely resolved the scope of protection under the First Amendment against compelled disclosure of one's identity. A few years ago, in the case of McIntyre v. Ohio Elections Commission, the court held that the Constitution wouldn't permit the author of political handbills to be punished for failing to include her name and contact information on those publications. That case, however, was decided on fairly narrow grounds, focusing on the specifically political nature of the communications and left open broader questions about more general protection for anonymity.

Those questions are going to loom large in the near future. The ease with which Internet users can communicate anonymously and avoid detection and expanding concerns, increasingly prevalent in the post-9/11 environment, about criminal activity over the Internet are likely to spark conflict. Courts will almost certainly have to jump into the fray.

Last month brought two developments on this front. In one, the Supreme Court of Virginia refused to quash a subpoena issued by a California court to America Online. The subpoena required AOL to reveal the name and address of a subscriber alleged to have defamed a California company on an Internet bulletin board. It's an issue that many companies are monitoring closely. In particular, businesses in intellectual-property industries are concerned with their ability to track down users who are misusing, as the companies see it, their intellectual property. AOL argued that forcing it to reveal subscriber information would "infringe on the well-established First Amendment right to speak anonymously" and that a commercial dispute between two private parties didn't constitute sufficient grounds for overriding this protection. The court rejected the First Amendment argument outright.

The government, too, is moving in this area. Word leaked out in late November that the Defense Advanced Research Projects Agency -- the folks who brought you the Internet back in the 1960s and, more recently, the highly controversial proposal for a Total Information Awareness database-mining program -- has been considering (though it has rejected it, for now) a surveillance technique it calls eDNA that would tag all Internet data with unique markers to make impossible the anonymous use of parts of the Internet. The proposal envisions a divided Internet with secure "public network highways," where identification would be required, and "private network alleyways," which wouldn't require identification.

When the forces of commerce and government are lined up, things usually happen. If there's to be any push-back here, it will come from the courts in the guise of expanded First Amendment protection for keeping one's identity shielded from scrutiny, or from an angry citizenry. Does the right to free speech encompass a right to speak without fear of retribution? We shall soon find out.

David Post is a Temple University law professor and senior fellow at the National Center for Technology and Law at the George Mason University School of Law. Reach him at postd@erols.com. Bradford C. Brown is chairman of the National Center for Technology and Law at the George Mason University School of Law. Reach him at bbrown2@gmu.edu.