That is a really good question, Lori.
To be honest, initially I did not know you *could* pin from a forum. (My bad in not knowing that.) I only found out after the tutorial video was pinned from the forum. The only things I don't want pinned are the pointed pen tutorials as I want to keep those as a special "bonus" for members only. Anything else I pin is fair game.
However, for everyone else's work, I want members feel comfortable posting here and not worried their practice or critique is going to get pinned on Pinterest. I think if people use common sense and ask if they are unsure, it should be fine. But if you have any doubt, you can always keep a private inspiration board.