Brooklyn artists have contributed so much to the world that it's hard to imagine one of their number taking something away.

Yet here we are at a seminal moment in geek despair, with the news that Paul Ingrisano has trademarked "π." for a variety of clothing materials, including hats and, gasp, T-shirts.

How is this even possible?

As Wired reports, Ingrisano is the man behind Pi Productions Corp of New York, a company that has secured trademark registration number 4,473,631.

This trademark is for "π" followed by a full point.

It so happens that custom, on-demand retail site Zazzle has been selling all sorts of π T-shirts in its online store. Then it didn't, as Ingrisano's lawyer issued a cease-and-desist letter (below), claiming that since January 28, 2014, his client has owned the trademark.

Not only did Ingrisano's lawyer want Zazzle to stop and stop right now, he also wanted to know what profits it might have made on Pi apparel in the time that his client owned the trademarked. He gave Zazzle 14 days to respond.

Zazzle complied with the request, saying that it affected thousands of products on its site. It's not clear, however, how many of the products might have used the actual "π." configuration.

On Zazzle's forums, reaction was swift and immoderate. Zazzle allows users to create their own designs. Many of its customers are convinced that their π designs don't infringe on thee trademark.

One, Viviandulies, angry that Zazzle appears to have complied, wrote: "I am familiar with the legal issue of 'likelihood of confusion' concerning trademarks. It doesn't mean that any usage results in a risk of willful infringement and I can only assume that you are aware of this fact. Especially with the math symbol the risk of confusion is minimal if the pi is presented in a a mathematical context or puns. Trademarks with pi are weak and you should know that."

She concluded with this message to Zazzle: "Stick where no grass grows."

Zazzle forum posters also discovered that Ingrisano has a pending trademark registration for I3, a very popular annotation of "I love."

The objections from those whose designs are sold through Zazzle may have had some effect. Today, certain π designs are back up on the site.

I have contacted Zazzle to see whether the site has decided to do a little less ceasing and lot less desisting and will update, should I hear.

It seems odd that a symbol that has existed for so long should suddenly be subject to such a draconian action on the part of a hitherto unknown artist. A trademark has to be surely more than just an already existing symbol.

Perhaps he thought that by applying for "π." he would get easier approval. And he did.

I wonder, though, whether the power of the world's geeks might ultimately prevail.

Updated 10:10pm PT: A Zazzle spokesperson told me: "After reviewing the takedown request more closely, Zazzle has decided to restore the "Pi" products. Zazzle is a marketplace for a community of artists, and we want to continue to support artists who are creating original artwork."

Zazzle Pi Trademark Letter