IIRC Google made a honeypot link and got it to show up on Bing without allowing it to be spidered directly (since nothing linked to it). However Microsoft resp

IIRC Google made a honeypot link and got it to show up on Bing without allowing it to be spidered directly (since nothing linked to it). However Microsoft responded that they used Internet Explorer or some other client side tech with the "use my searches" options turned on to go to the honeypot on google.com, leading to Microsoft to get a hold of it. So less of a "Microsoft steals Google results" and more of a "Microsoft follows Google results when you use their browser and don't tell it not to".