First of all, the usage of other people's artworks. Like in Youtube thumbnails, roleplay ... Stuff... (?), basically anything.
I absolutely don't mind that you do this. (altho if you use characters for RP i REALLY wish you didnt use my own characters. That really irks me out.)
I don't mind that my pictures are used for thumbnails at all. What i do mind is the lack of acknowledgement. I do a little dance seeing that someone actually did their effort to credit me, and sometimes i wish they would actually ask/or tell me, so i'm aware. I don't know its the little things you know?
I've lost quite some respect over time on YT creators who refuse