While Blok worked on her design, she and her colleagues agreed that the logo, like the software, should be open-sourced. “We decided it would be a collaborative logo that everybody in the world could customize,” she says. “That was pretty daring.” Most companies, of course, defend their trademark from copycats, and million-dollar lawsuits have been filed over the rights to corporate insignia. This one would remain free.

That is an amazingly gutsy move that has paid off tremendously.

I wonder what keeps them from getting ripped off by truly bad guys. 

... perhaps the design dna and ongoing open source environment of good intentions