The violation of privacy is Facebook reserving the right to use your photo on ads served on sites other than Facebook. Inside of Facebook, it's just creepy.
But its not. Its viewable to your friends only (who may be browsing a third party site). This information is not made public in any meaningful sense of the word public. Only those who were able to see your like on facebook will ever see it in the context of an advertisement. Hence, no privacy violation.