Update: On Friday afternoon, Comodo surrendered all claims to the trademarks. CTO Robin Alden wrote:
Comodo has filed for express abandonment of the trademark applications at this time instead of waiting and allowing them to lapse.
Following collaboration between Let’s Encrypt and Comodo, the trademark issue is now resolved and behind us and we’d like to thank the Let’s Encrypt team for helping to bring it to a resolution.
Comodo, the world’s biggest issuer of browser-trusted digital certificates for websites, has come under fire for registering trademarks containing the words “let’s encrypt,” a phrase that just happens to be the name of a nonprofit project that provides certificates for free.
In a blog post, a Let’s Encrypt senior official said Comodo has filed applications with the US Patent and Trademark Office for at least three such trademarks, including “Let’s Encrypt,” “Let’s Encrypt with Comodo,” and “Comodo Let’s Encrypt.” Over the past few months, the nonprofit has repeatedly asked Comodo to abandon the applications, and Comodo has declined. Let’s Encrypt, which is the public face of the Internet Security Research Group, said it has been using the name since November 2014.