I agree with you that the models are not technically underage. Moreover, I know from previous articles about AA that they make the models sign releases confirming they are of age. However, I think that makes it worse and I'd like to explain why.
We already know that what constitutes porn is in fact subjective and was "officially" defined as such by the Supreme Court:
http://en.wikipedia.org/wiki/Jacobellis_v._Ohio
So what I'd like to point out is that the very reason that AA needs that little signature is because they know they are (1) making pornographic ads and (2) using models that look underage. If either of those two were untrue, the free-wheeling, open-minded people at AA would surely not resort to legal means to cover their ass.
As far as not providing evidence, what is harder evidence than actual photos of AA ads? I don't see how it's relevant what website they are posted on. Photos are photos.
But hey, I am happy to link to more. If you don't think these are prime pedophile material, I don't even know what to say... you must be one "open-minded" dude.
http://www.gamesetwatch.com/2006_07_10_9.jpg http://www.wasuvi.com/images/scan0004.jpg http://www.adrants.com/images/the_tap_panty.jpg http://www.mediabistro.com/agencyspy/original/aaad.jpg http://www.jenisfamous.com/uploaded_images/leggings-720878.j... http://www.trendhunter.com/images/phpthumbnails/21343_1_230....
As for the photos: like I said before, they don't look underage to me. I've additionally checked this with a few people in other age ranges of both genders, just to be sure I wasn't crazy, and the consensus was that they all looked like adults.
P.S. The "If you don't agree with me, you're <insert x here>" approach is a bit silly. I do like to consider myself pretty open-minded, though :)
The link you provided doesn't count. First of all, it's on a humor site, and the article definitely seems to belong there. But more importantly, it provides no evidence that the models are underage, the photos it shows don't appear to be me to be of underage girls, the photos aren't quite pornographic anyways (though admittedly fairly close), and it doesn't even provide any evidence that AA attempted to represent them as underage.
I'm completely willing to hear that AA is making child porn--I have no affiliation with them or anything like that--but you haven't provided any evidence and therefore you shouldn't make the claim.