While I'm certainly not one that would normally defend MS, I think they have made the right decision in this case. It's a good thing to go after the fraudsters. Helps to keep the legit publishers, and the business model itself cleaner, and presents a better image to other advertisers, reassuring them that they are actively pursuing fraud.
MS's blog about it:
https://community.microsoftadvertisi...ick-fraud.aspx
And here:
http://microsoftontheissues.com/cs/b...ick-fraud.aspx