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".

User t0tenh0sen saw this while driving down the highway in NC.

"The Eternal Melody of Pi Base 12" ... The perfect melody exists encoded in the most basic mathematical constant. All it needed was some chords added to it and the notes to be timed properly.