Why Did Nintendo Sue Nyko?

Nintendo has recently sued Nyko Technologies for copyright infringement over Nyko’s new Kama Wireless Nunchuk.  While copyright infringement is nothing new (think Sony), Nintendo is not known for being so aggressive...and especially not towards products which they don’t even sell themselves.  Apparently, Nintendo sees it as an infringement on their patent designs and trademarks, and as such, are suing Nyko, claiming the company’s Kama Nunchuk “wholly appropriates the novel shape, design, overall appearance and even the color and materials used in the Nintendo Nunchuk controller”

If Nintendo is so concerned with copyright infringement, why don’t they go after the guys on Canal Street in NYC hawking cheap knockoffs. Why go after a company like Nyko?  And why sue over ridiculous things like “appearance” and “color?!” Nyko is a good company that makes
quality third party accessories. Products like this enhance the “Wii Experience,” boosting further interest in the Wii, and help drive sales for Wii games, systems, and merchandise.  Suing the companies that make these products is not going to help any of that, may stifle
further innovation, and will leave a bad taste in the mouths of many who hold Nintendo in high regard.

I guess the guys on Canal Street don’t exactly have deep pockets.