I've noticed a bit of confusion among EAs about whether CEA (or technically EVF) owns the phrase "effective altruism". I've heard a couple of EAs claim they have the trademark, or asserted some kind of ownership right against a scammer once. And I do have the impression that CEA tries to manage the EA brand in a way that suggests that they feel like they own it.
However, I checked the US Patent and Trademark Office's database, it shows trademarks on "Centre for Effective Altruism" and "Effective Altruism Global", but not "effective altruism". Is it even possible to have a trademark on the name of a philosophy? Is there some other area of law that is relevant?