[IcED]

It's an advertising campaign. An advertising campaign's first duty is to get you to notice it. It's second duty is to get you to think about the product/message. On both fronts, I'd say this campaign has succeeded.

There is nothing unethical about appearing nude. I'm sorry that some religious and cultural taboos compel you to feel that way.

Posing like Playboy Playmates in an attempt to save animals?
That is the most absurd idea ever.
I'm sorry that you seem to have no mind of decency.
(Which I have to say, you don't need any religious or cultural rule to tell you that being 'decent' is something we must follow, regardless of whatever path you believe.)
You might as well be hypnotized by these ads.

These ads sure does catch the attention of older audiences, but didn't PETA think that little kids will be seeing these ads?

You don't need to be nude to convince people to take action against animal abuse. And you certainly don't need sexual innuendos plastered all over to get them to understand the message of "Stop Animal Cruelty".