"Imitation is the highest form of flattery,"
I used to think the same way back when I was a newbie artist on the internet. But as I progressed and improved, and started putting a lot more work in to my art, I realized that I wouldn't like it very much if someone took my picture, pretended that it was their work, claimed my character as their own, and went so far as to actually use that character on a roleplay game or forum.