How to lock the skins directory?

Ive noticed on every site running yacs you can simply add in /skins to the end and show a list and actually go in and snake every file if you wanted :D. I was wondering if it was possible to lock or redirect this folder without stopping the skins from loading?

I am going to be putting some cash into one and while whatever i do end up with will also be offered to people i dont want the specific rendered one for my site open to the world or say some clownshoes that registers like drunkenheroes.whateverelse

Thanks,

FD