The non-profit Let’s Encrypt project has found itself in a kerfuffle with Comodo, one of the largest commercial vendors of website certificates. Comodo claims to be the worlds most widely used SSL Certificate Authority. The Internet Security Research Group started using the name Lets Encrypt publicly in November of 2014, and has repeatedly asked Comodo to abandon their trademark applications, directly and through our attorneys, but they have refused to do so.”]
Source: https://grahamcluley.com/lets-encrypt-comodo-trademark-tussle/