Norwegian companies have found their Google ads presented at the dubious file sharing search engine Isohunt. It looks like Ask.com is involved.

The newspaper Dagens Næringsliv reports that several Norwegian companies have found their Google Adwords/AdSense text ads on the notorious Canadian file sharing site Isohunt — a BitTorrent search engine.

Given that some of the companies belong to the record business — among them Sony BMG and the Norwegian media store Platekompaniet — the industry has reacted strongly.

Interestingly enough, Google has already excluded Isohunt as a Google Adwords partner, exactly because it helps users find illegal downloads.

Isohunt has managed to serve Google ads because another ad network apparently serves “surplus ads” from Google.

We were not aware that Google accepts reselling of ads of this kind, but it seems to be the only explanation.

Isohunt does serve pay per click text ads in their search results. In our tests we have found that the URLs redirect clicks through Ask.com. Ask displays Google ads at its own search site. It may be that someone has found a way of using Ask to serve Google ads at Isohunt.

In any case, Google has reacted promptly. The company says it is sorry about what has happened and is now trying to stop further Google Ads from being displayed at the Isohunt site.

Jan Grønbech of Google Norway says that under normal circumstances advertisers may remove sites from the Google advertising network:

“In this case it has been impossible for the advertisers to find out that their ads have been displayed over at Isohunt. This means that the advertisers cannot be blamed for having their ads presented there.”

Isohunt presents a large number of Norwegian films and CDs for free downloads, in violation with international copyright laws. It is the third largest site of its kind, after PirateBay and Mininova. Isohunt has been sued by the Motion Picture Association of America.

UPDATE JAN 25: JenSense has an interesting comment to this article where she confirms that Ask.com is using ads as backfill. Moreover: Isohunt is using Ask’s version of the ads. Jennifer Slegg of JenSense adds:

“You have to wonder how long Ask.com will be allowed to do both arbitrage and allow third parties to run their ads. But, as it should be noted, the ad deal between Google and Ask was signed in November 2007, and the deal was a five year deal worth $3.5 billion dollars. So this could mean that there could be another nearly 4 years of these kinds of incidents.”