Google unveiled the results of a sting operation which shows that Microsoft have been capturing Google search results and placing them into the competing Bing search engine.
The issue relates to Microsoft's Internet Explorer and the Bing Toolbar which apparently passes search queries and visited web pages to Microsoft servers which are then later used to generate results in the Bing search engine.
"I've spent my career in pursuit of a good search engine," said Google search ranking fellow Amit Singhal. "I've got no problem with a competitor developing an innovative algorithm. But copying is not innovation, in my book."
According to a Search Engine Land report, red flags were raised in October of last year when the firm noticed a increase in overlap of Google's top 10 search results with those of Microsoft's Bing.
To confirm the suspicions, Google set up an elaborate sting operation where it for the first time ever manipulated search ranking for around 100 'synthetic' searches of nonsense terms. The terms were chosen because they returned no matches on Bing or Google.
Google then placed a honey pot page to show up in top position for the synthetic search and then on the 17th of December Google engineers ran the test queries from laptops at home running Internet Explorer with Suggested Sites and the Bing Toolbar enabled.
By the 31st of December the search results began to appear on Bing.
Microsoft was unrepentant, calling the sting a "spy-novelesque stunt".
"We use over 1,000 different signals and features in our ranking algorithm," said Microsoft Bing veep Harry Shum in a blog post.
"A small piece of that is 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."
While Search Engine Land's Danny Sullivan pointed out that the install options for IE and the Bing Toolbar clearly mention the use of the user's search queries, he nevertheless concluded: "I've got some sympathy for Google’s view that Bing is doing something it shouldn't."