But if someone share it here , won't Ginhaha know which one bought it ?
That would, at least, require some effort from the artist, such as:
1 - knowing about this place
2 - caring about their stuff being leaked
3 - implementing some kind of tracking method in their works, for each platform and user
4 - checking every leaked work, granted that steps 1 and 2 are met, in order to find the culprit thanks to step 3
Steps 3 and 4 would basically be impossible due to how much time consuming they are.
Only a truly paranoiac person would go this far. So don't worry, there's no risk of it happening.