Originally Posted by Brad M
If this Locomotives for Mother Earth company is really the friendly organisation they make themselves out to be they wouldn't be coming down on some kids pressing t-shirts for fun.
The OP hasn't said who, if anyone, is claiming rights to the trademark. All he said is that he got an email telling him that the phrase was copyrighted. He didn't say who sent him the email and whether they claim to represent someone who has rights to the name.
A simple google search will find that the trademark of One Less Car has been discussed on a couple of other cycling forums. Perhaps someone who recalled one of those discussions sent the email
BTW, onelesscar.org is owned by OneLessCar, Inc (as indicated on their website). OneLessCar, Inc. is the same corporation as Locomotion in Favor of the Earth, which owns the "One Less Car" trademark.
Locomotion in Favor of the Earth was formed in 1999. In 2002, the corporation changed it's name to OneLessCar, Inc. The President (at that time) was Paul Lebow, and the Treasurer was James D. Vance. Principal offices of OneLessCar, Inc. were in Annapolis, Md.