Are my galleries protected from Pinterest use, or can I customize my SmugMug site to block out Pinterest use and abuse?
If you want to be a bit more explicit about your anti-pinterest interest:
From the help pages linked off http://blog.pinterest.com/post/17949261591/growing-up.
This works, put the code in the head tag of your Advanced Customization (power and pro accounts only).
In my testing I have found that Pinterest does seem to respect the gallery protected setting. That way you can allow pinning from specific galleries and block it from others. I would recommend you set the galleries to protected if you are a Power or Pro user. I would also disable external links as that can also help.
For total site Pinterest blocking, Power and Pro users can add