Here is a good opinion piece from the washingtontimes.com
Late last month, Penn State climate professor Michael Mann turned to the Superior Court of the District of Columbia to sue several individuals who dared satirize his work. Mr. Mann became famous three years ago when leaked Climategate emails referenced Mr. Mann's "trick" used to "hide the decline" in global temperatures, inspiring countless parodies and scathing commentary.
They even mention Minnesotans For Global Warming:
This isn't the first time Mr. Mann has turned to the judiciary to silence critics. In 2010, Minnesotans for Global Warming produced a viral YouTube video entitled "Hide the Decline." Over 600,000 people viewed the animated likeness of Mr. Mann singing lines such as, "Michael Mann thinks he's so smart, totally inventing the hockey stick chart." The popular video was pulled after the group received a cease-and-desist letter. "My first reaction was, 'Wow, I guess I hit a nerve,'" Elmer Beauregard, the video's creator, told The Washington Times. Mr. Beauregard and his colleagues lacked the resources to mount a proper legal battle, so he is glad National Review and CEI aren't backing down.