Common sense may seem in short supply in today's litigation-happy world, but it got a boost recently from -- of all places -- Florida, where a federal judge tossed out a lawsuit claiming that Southwest Airlines' Web site violated the Americans with Disabilities Act. The decision is good news for the Internet, and for consumers, because it blocked what likely would have become regulation-by-litigation of Web site design.

The lawsuit, brought by Access Now, an ADA advocacy group, claimed that Southwest violated the Act because its Web site was insufficiently accessible to blind persons. Specifically, the plaintiffs faulted Southwest for not providing text in a format that could be read by synthesized speech technology.

What about the fact that the relevant section of the Act applies only to "places of public accommodation"? No problem, said the plaintiff's lawyers: Certainly "place" can't be limited to the narrow confines of the physical world. Cyberspace, too, is a place.

Unfortunately for the plaintiffs, although the ADA is famous for its ambiguity, its text is pretty darn specific on this point. It actually lists what it considers a "public accommodation." It includes inns, hotels, motels "or other place[s] of lodging." Also restaurants, bars, movie theaters, concert halls, auditoriums, bakeries, grocery stores, laundromats, dry cleaners, banks, and so on. The drafters practically gave specific addresses. And not a Web site among them.

But the lawyers maintained -- presumably with a straight face -- that Southwest's Web site was covered under the Act as a place of "exhibition, display and a sales establishment." Yet the judge, Patricia Seitz of the U.S. Southern District of Florida, didn't buy it.

Apparently an old-fashioned judge, Seitz even used Latin, citing the doctrine of ejusdem generis: "where general words follow a specific enumeration of persons or things, the general words should be limited to persons or things similar to those specifically enumerated." Or, as they say in pre-school, "one of these things is not like the other."

Is this a quirk in the law? A loophole in the ADA that policymakers should patch? No. There are good reasons not to drag cyberspace under the ADA. Such regulation is likely to impose considerable burdens on Web site owners -- exactly the wrong prescription for the ailing Internet economy, as well as for consumers.

ADA advocates say the costs of making sites accessible are minimal. But where that's so, companies tend to act voluntarily. After all, they make money by helping, not hindering, potential customers.

But with requirements ranging from providing transcripts for audio files to checking color contrasts, the burden can be substantial, and the costs can add up quickly. That could be why the list of sites not meeting accessibility standards includes not just many airline sites, but even some government sites, such as that of the Commission on Civil Rights.

Still, ADA advocates argue that if physical establishments can learn to live with the additional costs, cyberspace operations can too. That's too complacent a view. Apart from lawsuit-happy trial lawyers, few see the current ADA as a model of perfection. If applied to the economically fragile digital world, the potential damage would be considerable.

The Manhattan Institute's Walter Olson warns, for instance, that Web design creativity and spontaneity could be stunted, as publishers feel constrained to use only officially accepted tools. Amateur Web sites would be winnowed as legal and technical rules limit the art to professionals. So much for "blogs."

What about the First Amendment implications? The Internet is foremost a tool of communication --- but ADA mandates could lead to regulation of content unimaginable for newspapers or magazines. Current guidelines, for instance, say that sites should "use the simplest and most straightforward language that is possible," raising the prospect of judges sitting in the editor's chair.

None of this is to say that making the Internet accessible to the disabled isn't a worthy goal. It is, and efforts to do so where practical are to be applauded. But such efforts must be voluntary; we shouldn't be subjecting the Internet to regulators and trial attorneys. Judge Seitz was correct: The ADA does not -- and should not -- apply to cyberspace.

James L. Gattuso is a research fellow in regulatory policy at The Heritage Foundation, a Washington-based public policy research institute.