Google has been suspecting for a while now that Bing is ‘copying’ their results to a certain degree. One Google engineer wouldn’t go so far as to call it stealing – but he likened it to running a marathon being carried on someones back the whole way and then jumping off at the finish line.
So Google sets up a sting operation - by hardcoding search results for certain gobbley-goo phrases (which they’ve never done before) to see if similar results showed up in Bing. A few weeks later – they did!
Read the whole facinating article, written and researched by Danny Sullivan: