The mark consists of the pi mathematical symbol followed by a period.Even though the trademarked symbol is π followed by a period, Wired reports that Ronald Millet, the attorney for Ingrisano, has demanded that the website, Zazzle remove all merchandise containing the symbol π, whether or not the symbol is followed by a period:
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.
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Attorney Millet defends the cease-and-desist letter. He says that to his knowledge none of the designs sold through Zazzle included the exact trademark π.—pi followed by a period—but some of them were confusingly similar to his client’s design.
“Some clearly have a pi sign and look similar enough that folks out there might confuse it with products that my client also sells,” he says. “I saw the back and forth on the blogs of some of the sellers on Zazzle expressing their disappointment. I can see that as an understandable reaction, from a personal standpoint.”At least Millet is sympathetic towards those who are reacting to his "missing the point of trademark law" (those are Professor Mark Lemley's words, not mine). Underhill has some more critical commentary.
Here, Ingrisano presumably added the period in the first place so the Patent & Trademark Office would be less likely to reject it as too "generic" to register. (See, e.g., USPTO, "Basic Facts About Trademarks.") If so, then he shouldn't be able to turn around and claim that a pi symbol without the period might confuse consumers into thinking an item is one of his products. And since his attorney has admitted that as far as they know, there are no products actually bearing a "π." symbol being sold anywhere on Zazzle ... well, it almost seems like he shouldn't have sent the letter in the first place, doesn't it?I don't have much more to add, other than providing the full demand letter to Zazzle below. I think that the letter speaks for itself, so I won't criticize Ingrisano's pointless abuse of trademark law any further.