I wasn't aware of this, but it still seems like a thread worth pulling on. You're assuming, right? The reason I ask is that using any third-party company seems inappropriate. Even more so when Google has plenty of domains of its own to test against. Even more so when it is against a media/advertising company. And again, even more so against a company that changed from Google to Bing to power their search function. It seems to be an inappropriate or poor choice, doesn't it?

There's no smoking gun here, but I don't think that concern might be dismissed out of hand. It might be good to see what Yahoo's take on this. This could even evolve into participation by the US Attorney General. I'd like to know more, either way. Like if Yahoo was independently added to the list at a later date, or if it was there from the start?