It used to be the intellectual property of the guy who made it, but they've since given it up as creative commons. Guess he made enough off of royalties

[–] b3nsn0w@pricefield.org 7 points 1 year ago

wikipedia also has this to say about it:

you can trademark things like this, but copyright only applies automatically to human authorship, so something that has less entropy than the average midjourney prompt (which is explicitly classified as "not authorship") is probably a safe bet to ignore. and i don't think a trademark would be granted here either, but idk what the uspto would have to say about this.

regardless, slapping a CC BY-NC-SA 4.0 on it, which is what the original designer did, is a pretty good way to tell the corpos that this isn't your cash cow, fuck off. and if that's what they did, that's commendable, but i'm still a bit afraid because it very much up to the original creator in these situations and they can do damage to communities with shit like this if they decide to.