Multiple sellers on online marketplace Zazzle were shocked to find last week that their designs had been taken down as a result of a cease and desist notice by a fellow named Paul Ingrisano, alleging that their work infringed upon his registered trademark.
The trademark in question is the symbol for pi. It refers directly to the symbol followed by a period. Even though the sellers on Zazzle did not use a pi with a period, they still received cease and desist letters.
Wired spoke to Mark Lemley, a law professor at Stanford University, who said: "if you want to sell T-shirts and on the tag your brand name is the symbol pi, I think that's a reasonable trademark. But if what you want to do is actually prevent people from using the symbol pi on a T-shirt, then I think you're missing the point of trademark law."
So why did Ingrisano own the trademark? According to his Facebook page he works at "Pi Production Corp".