Was thinking of adding an avatar (random image I like off a search) and got to wondering this.
I think it’s fine if you’re not claiming it is yours. And most people assume that any generic/immediately recognizable avatar is just an image off the internet that the user just likes.
Though there’s maybe a weird grey area where if you use artwork from someone that isn’t like… a super established artist (hard line to draw) it’s kind of iffy. I wouldn’t feel right using someone’s drawing off Instagram. But plenty of people use anime avatars from manga etc. and I don’t see an issue.
Not the most important topic in the world but I thought it was fun to think about.
It’s almost certainly “fair use”, in terms of the American copyright, as what you use as an avatar has absolutely no market impact on the original work.
Ethically speaking I don’t see a problem with it unless you try to pass it off as your own work, do it against the wishes or the original creator, represent that work in a bad light, etc.
Fair use requires you to analyze or comment on the work or transform the original work in some way, non-commercial use isn’t enough on its own.
The real reason it’s “ok” is that it’s unlikely the owner would be able to prove damages from someone using their image as an avatar so it’s not worth taking anyone to court over it because all they would get is the judge ordering them to stop and a C&D is cheaper if the owner really cares about stopping you.