Thanks 
disneyboy, that's pretty huge news.
Anyway:
"This was a photo which was taken privately," Hudgens' rep said in a statement. "It is a personal matter and it is unfortunate that this has become public."
Are you guys serious? You're getting all worked up over Vanessa, who wanted to stay a Disney girl and actually liked being in a successful but "wholesome" family-friendly franchise, would want a naked picture of her passed around which she knew would ruin her chances? Please. Today, children want to be seen as adults, as well as be seen as sexy. They want people to love them not just because of what they do, but how they look, how they were born, what they will always be (without surgery).
I'm gussing Vanessa took the picture privately for some boy she liked, if it was Zac or otherwise, or just for herself, to feel good about herself, to feel beautiful, and perhaps the photo taker or someone close to her she gave it to put it on the internet. I'm sure she wouldn't want a friend ruining her career, so perhaps she was just careless or too trustworthy, but unless she secretly wanted out just like Zac (and Zac is staying with HSM!), I don't think she wanted this to happen.
So stop judging her!