This Guy Trademarked the Symbol for Pi and Took Away Our Geeky T-Shirts | Threat Level | WIRED: At issue is U.S. trademark registration 4,473,631, issued to one Paul Ingrisano, aka “Pi Productions Corp” of New York. In January, the U.S. Patent and Trademark Office gave Ingrisano a trademark on the symbol π.—pi followed by a period—a design Ingrisano uses on T-shirts sold at some brick-and-mortar stores.
When Ingrisano discovered that California-based print-on-demand outlet Zazzle offered an array of clothing items that feature pi–which represents the ratio of the diameter of a circle to its circumference–he had attorney Ronald Millet send the company a strongly worded cease-and-desist letter this month demanding their removal.
