For the last several weeks, a company known as Flatplanet.net has been hijacking Gnutella searches online, responding to queries on the network with ads for its software--a product that allows its customers to post their own ads on the Gnutella network.
Unsolicited advertisements for such things as pornographic Web sites have appeared on the Gnutella network. But because the Flatplanet ads are more sophisticated than earlier Gnutella advertisements, and because they promote a product designed for creating new ads, they have sent ripples of concern through the loosely organized open-source community.
"This wouldn't be the first time that Gnutella has been spammed," said Gene Kan, one of the developers who has taken a lead in the Gnutella development world. "But it's the first time there's been a commercial effort targeted at people who want to spam Gnutella."
Although the Flatplanet Web site has been temporarily taken down by its network service provider after complaints about its software, the issue has set off a debate about how the file-sharing world can protect itself from advertisers.
"Once you have a little programming knowledge, it's not hard to respond to any query you want. There are no constraints," said Kelly Truelove, CEO of Clip2.com, a company that provides data and technical information to Gnutella developers. "It could be a huge problem for Gnutella."
The Gnutella technology, originally developed by programmers inside America Online's Nullsoft, works much like Napster but without a central server. A computer running the program connects directly to a handful of other computers, each of which are connected to another handful, creating a daisy chain of members that quickly becomes enormous.
But because there is no central point that monitors connections or traffic on this ad hoc network--and no company responsible for the software that all the computers are using--it's difficult to keep tabs on what happens.
Developers say this has led to problems with a different kind of spam, as beta or badly written versions of the Gnutella software send poorly formed results onto the network, using precious bandwidth.
But it's the deliberate spam such as advertisements that developers are now looking to stop before it gets out of hand.
Flatplanet defends its practice, saying Gnutella ads aren't spam because they're not as intrusive as unsolicited bulk email.
"People are upset that they have to look at an ad because it gets in the way of stealing music. It's a little laughable," said Rob Smith, one of the partners in Flatplanet. "But you get lots of results you're not interested in with every search. You don't have to look at them; you don't have to download them."
Most Gnutella advocates aren't sympathetic. Some people have mounted campaigns to track down early advertisers and contact their Internet service providers, hoping to unplug the advertisers. A few Gnutella developers have put rudimentary filtering capabilities into their software. Still more are talking about ways to improve the filtering features inside the network.
One idea, originally posted pseudonymously on the Slashdot.org community site, is sparking considerable interest among developers. Under that model, the Gnutella software would send a test search composed entirely of random characters. Any computer that responded to that meaningless string would then be filtered out of the next, real query.
Others have discussed setting up trusted third-party sites, which would review files on the Gnutella network and brand them as spam-free. Software could be configured to accept only files that had been approved by one of these groups, developers say.
All involved, however, are aware that the issue is an arms race in its early stages, as advertisers work out ways around the filters.
"The Gnutella community is looking for ways to block us," Smith said. "We will in turn find ways to circumvent the blocks, and so the battle rages on."