There is a major scandal brewing in the tech world this morning that has the potential to greatly tarnish the reputation of Bing, Microsoft’s Google-challenger. According to Search Engine Land‘s Danny Sullivan, Google thinks that Microsoft is copying some of its search results. That’s about as serious an allegation as there can be in the search engine world. In an early statement, Stefan Weitz, Microsoft’s director of Bing does not deny this and told Sullivan that Bing uses “multiple signals and approaches” when thinking about ranking.

So what happened? According to Search Engine Land, Google noticed that some of Bing’s search results looked more and more like Google’s over the last few months. In order to test this theory, Google set up a sting operation. Starting in mid-December, Google engineers used laptops that ran Internet Explorer and with both the Suggested Sites and Bing Toolbar turned on to search for around 100 terms that were either made up or barely ever searched for. Among these terms were nonsense words like hiybbprqagindoswiftjobinproduction and mbzrxpgjys. Most of these returned either none or very poor results on Google and none on Bing.

[notification type=”alert”] Update: Microsoft just published an official reaction on the Bing blog, acknowledging that it uses” the clickstream data we get from some of our customers, who opt-in to sharing anonymous data as they navigate the web in order to help us improve the experience for all users.”

Harry Shum, Microsoft’s corporate vice president for Bing, argues that Google created this controversy as a publicity stunt: “What we saw in today’s story was a spy-novelesque stunt to generate extreme outliers in tail query ranking. It was a creative tactic by a competitor, and we’ll take it as a back-handed compliment.”

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Hiybbprqag bing 1

Google then set up fake search results for these terms that were accessible over the Internet but, given the nature of the search terms, would never be seen by real users. After just two weeks of running this experiment on these laptops with the Bing toolbar and IE’s Suggested Sites feature turned on, Bing started to return the exact same results for the terms used in Google’s honeypot sting. It’s important to note that this only happened for 7 out of the 100 terms Google experimented with.

Using IE, Suggested Sites and the Bing Toolbar to Copy Google Search Results

How did this happen? The likely explanation for this is that Bing uses the signals it gets from users who use the Bing Toolbar and Suggested Sites features to enhance its own search results. So whenever somebody who has these tools installed searches on Google, Bing gets this information. As Sullivan points out, this is perfectly within the realm of Microsoft’s privacy policy, but most users are likely not aware of it. Basically, Bing looks at what Internet Explorer users are clicking on when they use Google and then molds its own search results accordingly.

While that’s oddly clever and likely benefits Bing’s users, it also doesn’t feel right at all. The evidence, as presented by Google, is clearly damning for Bing. We expect to hear more from Microsoft about this over the course of the day and will update this post as warranted.