I'm actually a bit surprised by the reactions here. Since when is css copyrighted? Where are the numerous lawsuits against Pinterest "clones" for having a grid layout etc.?
Sure, it's a shame, but css, like html and javascript, is not a protected source. It's run client-side. Would you rather just receive a image/png from websites?
EDIT: I know someone who've experienced something very similar (with css prefixes obviously referring to his site rather than the microsoft.cn clone).