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?
Addendum: we have in rare instances attempted to prevent people acting in ways antithetical to EA principles from identifying themselves with EA (example), but it remains the case that we do not generally do this among members of the community acting in good faith.