I did something like this once. Someone kindly shared me some scans of a rare comic, and I turned around and posted them on 4chan without even thinking about it. Ten seconds of clout from ppl who only cared that I was providing content. Years later I still regret it.
People are gonna leak shit, so if you want to be that type of person who joins just to leak everything, you do you, but don't pretend to be their friend. Kemono is the worst too, your friend can literally never get it removed and will get doxxed if they try. What a shitty thing to do.