Last night, Google published a blog post on their webmaster central blog notifying affiliates that if their sites do not add any value, then they may be penalized. Google said it pretty clearly:
If your site syndicates content that’s available elsewhere, a good question to ask is: “Does this site provide significant added benefits that would make a user want to visit this site in search results instead of the original source of the content?” If the answer is “No,” the site may frustrate searchers and violate our quality guidelines.
Google's webmaster affiliate guidelines can be read in detail over here.
Google hinted twice, one in the blog post and once in Matt Cutts tweet that this is seen a lot more in the adult industry. Matt Cutts said, "good reminder about thin affiliates, esp. in porn." Matt added, "Cookie cutter sites usually don't add value."

Google's Zineb Ait Bahajji added on Google+, "if your site is syndicating content from another website and does not add any value to the users, Google may take action against it."

So it seems something is going to happen shortly to affiliate sites in the adult industry. This is Google's way of breaking spirits in a slow and repetitive way.
Google Warns Affiliates: If Your Site Doesn't Add Value, You May Be Penalized

Don't violate their "quality" guidelines

I guess they are preparing another major cleaning update...