MONSIEUR, DO YOU YAHOO?

Sick of the American legal system? Take a break with me, andmarvel at the curious workings of French law.

By now you've heard that a French judge, Jean-Jacques Gomez, hassaid that Yahoo must devise a way to prevent citizens of France fromvisiting parts of the Yahoo site that contain anti-Semitic and pro-Nazi materials.

American justice always provides a surfeit of goofy court rulings,so we scarcely need to import fresh nonsense from Paris. But ratherthan rail against the injustice of the Gomez decision, let's focus ona more practical question: Can it be enforced? Can an Internetcompany block access to citizens of a particular country, whileleaving the rest of us free to surf wherever we wish?

It turns out that there are a number of companies working on theproblem. As fate would have it, one of them, New York-based InfoSplitInc., was founded by a transplanted Frenchman, Cyril Houri.

"We didn't design this technology for filtering purposes orcensorship," Houri says.

InfoSplit was meant to let Internet advertisers target theircommercial blandishments by geography. With InfoSplit, they couldsell baked beans to Bostonians and surfboards to San Diegans.

It works because the Internet makes no secret of a user's generallocation. Every time you send a message, you reveal the set ofnumbers used by the Net to identify your computer - the "IP address."This information tells the other computer where to send its response.But it can also be used to trace you.

On Windows and Unix computers you can easily run a "traceroute"command that will let you track someone's IP address backward throughthe Internet, thus giving you a fairly accurate idea of the person'sphysical location. InfoSplit uses this method to find people.

When I entered its Web site, it instantly greeted the visitor fromBoston. Houri says the same principle could enable Yahoo to identifyvisitors from France, and lock them out of some parts of the site. Hesays that eBay and a Saudi auction site both have expressed interestin the InfoSplit system.

Houri's method isn't the only way to track IP addresses. There aremore than 4 billion available addresses, assigned in big chunks tocorporations, government agencies, and Internet service providers.Want to know which addresses are owned by, say, The Boston Globe?Just go to www.ipindex.net and look it up. It's public record.

NetGeo Inc. of Mountain View, Calif., uses its database ofassigned numbers to instantly look up incoming addresses and locatethe Web surfer.

"We can determine the physical location of someone . . . basicallydown to the city level," says business development manager LanceJacobs. "We're working on the technology to get it down to the ZIPcode level."

Both Jacobs and Houri say their systems would have no troublefiguring out whether an incoming Web visitor was in France or inFramingham. So maybe the French court order is reasonable after all.

Not according to Yahoo attorney Greg Wrenn.

"The language [of the order] says we're supposed to make itimpossible for users from France to access certain materials," hesays. And the technologies offered by NetGeo and InfoSplit don't comeclose to meeting that standard.

Both companies admit that their systems are stumped by serviceslike Anonymizer and SafeWeb, which conceal a surfer's true IPaddress.

The same problem arises with French subscribers to America Online.Remember that AOL isn't really part of the Internet. It's a separate,private network, and users aren't given IP addresses.

InfoSplit and NetGeo can spot AOL and "anonymized" visitors, butcan't tell whether they're from France. What would Judge Gomez haveYahoo do - block them all?

Besides, identifying French Web surfers isn't the toughest part.Yahoo also must rummage through trillions of bytes of data stored onits servers and identify all references to Nazism. Then somebody willhave to create a separate index of the pro-Nazi materials, whileallowing the anti-Nazi stuff to pass.

No indexing program yet devised can manage this, and if you don'tbelieve me, just go to Yahoo and run a search under "Nazi." You'llsee a link to US government archives of Nazi documents, for use byscholars. You'll also see the home page of the American Nazi Party.

The computer that created this index couldn't gauge the moralworth of these two sites; maybe there's a French computer that canmanage it.

Or better yet, a French judge. This Gomez fellow obviously has toomuch time on his hands, to judge by his wacky Yahoo ruling. Perhapshe should be assigned to enforce it. We can put him to work 18 hoursa day, scouring Yahoo's vast archives for pro-Nazi sentiments withthe Ahab-like diligence of a Democrat in search of dimpled chads.

Ridiculous? No more than Gomez's ruling. It's a pity that some inFrance wax nostalgic for the Fuehrer, but every country has its shareof cranks. I only begin to worry when their ravings have the force oflaw.

Hiawatha Bray is a member of the Globe staff. He can be reached bye-mail at bray@globe.com.