A patent described in a WIPO filing as a "method, apparatus and system for interfering with distribution of protected content" over peer-to-peer networks is now being pitched to businesses large and small as an ad-delivery device.

The patent, filed in 2006, is held by Bernard Trest, currently president of PeerMatrix. The technology travels under the trade name of "AdMorph," and the software was announced on Saturday.

The would-be advertiser downloads a copy of the software; prepares an "ad" he wishes to distribute; and logs into LimeWire, eMule or another peer-to-peer network. An ad can be any file, even an executable, and have any name. When a user searches on, say, "Happy Birthday," the PeerMatrix software sends over a copy of the ad-file -- renamed to "Happy Birthday," or whatever the search term was.

PeerMatrix makes money from this by piggybacking onto the download and distributing additional ads along with the original. According to the company's FAQ, a paid version is in the works that will distribute only the original advertiser's content.

The PeerMatrix Web site compares the system to Google or to banner ads, and Trest says that "by opening up P2P users to advertising, we plan to become the search engine of P2P ads," though PeerMatrix ad targeting doesn't currently go much deeper than allowing would-be advertisers to focus on specific words and geographic areas. The company describes itself as having been founded in 2004 to provide advertising solutions for file-sharing networks.

That's an interesting way of putting it, since in his 2006 WIPO patent-application description, Trest opens by stating the following: "The proliferation of the Internet, and in particular of Peer-to-Peer (P2P) networks has resulted in widespread unauthorized distribution of content covered by copyright and other intellectual property laws." He then goes on to describe his technology as "automatically taking an interfering action in respect of the requesting device" -- that is, automatically obstructing the peer-to-peer user's download of the content she was actually seeking.

PeerMatrix's FAQ raises the question of whether its service is simply spamming, and responds, "No. PeerMatrix advertising is similar to text ads or banner ads that you find on major search engines as your ads only appear when a P2P user conducts searches."

However, keepers of peer-to-peer networks might not see it that way.

Over at TorrentFreak, blogger "Ernesto" called for developers of file-sharing applications to filter the new "spamming tool" (his words) whenever possible. He quoted an emphatic agreement by FrostWire lead developer Angel Leon, who added, "This is nothing but good old fake search results, otherwise known as spam, and it's always been in the interest of the community to remove these results."

And ad-supported MP3Rocket does exactly that, telling the watchdog site p2pnet, "MP3Rocket currently has technology to block PeerMatrix's newest AdMorph or phony video file technology."

Whatever P2P keepers think of PeerMatrix's definition of spam, though, you've got to admit that -- as the company points out -- it's all perfectly legal as far as copyright goes.

"Using P2P networks is only illegal if you use the network to distribute someone else's copyrighted material," explains the FAQ. "Since PeerMatrix distributes advertising you've created yourself, you have the right to make your ads available on P2P networks."