Google very publicly called out Microsoft's Bing search engine claiming that it copies it's search results from Google. Google engineers were so sure that there was something suspicious going on with Bing Search Results that they set up a sting operation designed to trap Bing and prove that the Microsoft search engine is simplypulling information from Google. They created intentionally ludicrous searches with equally ridiculous search results, and then waited for that information to propagate to Bing.
The evidence seems damning. There is no denying that the gibberish queries planted by Google return the same results in Bing. Microsoft, however, denies that it "copies" Google, but rather that it tracks a variety of metrics for ranking sites and delivering search results, and that the Google sting evidence is actually just proof of common search indexing practices.
Whether Google uncovered some nefarious activity on the part of Bing, or Google simply gamed the system to entrap Bing, the fact is that Google is closely watching Bing, and is investing time and effort in understanding the metrics and algorithms used by Bing to index sites and generate search results.