[EDIT:As Michael Foord points out in the comments, the actions described below were taken by a company with which Microsoft had contracted. Microsoft appear to have acted in good faith once the duplicity was discovered].
I'm not terribly happy with the "Evil Empire" theory of Microsoft. There's little doubt that when the company was younger it was an aggressive competitor up to and occasionally beyond the limits of the law, and there was a culture of "what's good for Microsoft is good for the world". The company has been known in the past to take information obtained from smaller partner companies and use it to build competing products and services, to the partner's disadvantage.
But I know quite a few people who work in Microsoft, and none of them are the kind of people who I would expect to indulge in any kind of ethically questionable behavior. I have assumed, perhaps naively, that as the company grew its culture would be molded more by the requirements of the legal jurisdictions it operated in, and less by the cowboy ethic of earlier years. Silly me.
The latest and most egregious example of Microsoft rip-off behavior comes from China, where the Microsoft subsidiary in November published a "Chinese copy" of Plurk Asia's micro-blogging service. Following the link will make it obvious this isn't just a cosmetic copy - the similarities appear to extend deep into the code base.
Given Microsoft's holier-than-thou approach to piracy issues, particularly with regard to the Chinese and other Asian markets, it makes one wonder who took the decision to go ahead with this project, and why heads haven't already rolled - or maybe they have? I hope (but alas sincerely doubt) that it costs Microsoft a lot of money to put this right, since it appears that money is the only thing that Microsoft understands.