Fan art does belong to the artist - hence why it is called fan art. The character belongs to the creator. For instance: You cannot come to my page, pick a fanart I did and repost it on your page. That is in fact theft.
This is an art site, not a site to post images you like that you did not draw. If you like an image, you add it to favs.
By your statement, you promote art-theft, as minute as you may think it is. As an artist, you should know better.