A spat between Internet titans heated up with Microsoft angrily denying that Bing copies Google's search results and the world's top online search engine adamant it has proof.
Microsoft senior vice president Yusuf Mehdi went on the offensive in a blog post that accused Google of tricking Bing with a "honeypot attack" too sweet to resist.
"In simple terms, Google's 'experiment' was rigged to manipulate Bing search results through a type of attack also known as 'click fraud,'" Mehdi said.
"That's right, the same type of attack employed by spammers on the Web to trick consumers and produce bogus search results."
Google held firm that it conducted a simple, honest experiment that showed Bing copied its search results and that rather than gripe about getting caught it should simply stop doing it.
"Some Bing results increasingly look like an incomplete, stale version of Google results -- a cheap imitation," said Amit Singhal, one of the company's search engineers, on Google's official blog.
Google had noted that in the summer of 2010 Bing did not return any results for a misspelled search for the surgical eye procedure "tarsorrhaphy."
"Later in the summer, Bing started returning our first result to their users without offering the spell correction," Singhal said. "This was very strange."
The experiment was repeated with nonsensical searches, including "hiybbprqag," "delhipublicschool40 chdjob," and "juegosdeben1ogrande," which Google had designed to link to a single unrelated result.
Google engineers used their company's search engine and Microsoft's Internet Explorer web browsing software to search on the fabricated terms that generated orchestrated results.
Within weeks, Bing offered the same results for searches on the made-up terms, according to Singhal.
Google equated the experiment to releasing intentionally false information and following its trail.
"We do not copy results from any of our competitors," Mehdi said. "Period.
"We have some of the best minds in the world at work on search quality and relevance, and for a competitor to accuse any one of these people of such activity is just insulting," he continued.
Microsoft argued that search feedback from users of Internet Explorer is "one of more than 1,000 signals" taken into account by its formula to match online queries with results.
Bing gets information from users who agree to share anonymous data "as they navigate the web in order to help us improve the experience for all users."
Google found it suspicious that a fictional search term and fabricated results popped into Bing if they were just one signal in a sea of more than 1,000 signals considered by Microsoft's ranking software.
"However you define copying, the bottom line is, these Bing results came directly from Google," Singhal said in a blog post detailing the sting operation.
"To those who have asked what we want out of all this, the answer is simple: we'd like for this practice to stop."
Bing corporate vice president Harry Shum dismissed Google's experiment as "a spy-novelesque stunt."
"It doesn't accurately portray how we use opt-in customer data as one of many inputs to help improve our user experience," Shum said.
"We all learn from our collective customers, and we all should," Shum said.
Explore further: New approach to online compatibility