I pasted my own work into the text box, and it tried to charge me money. It also let me buy, "fuck you, ever heard of fair use". (OK, I used a fake credit card number, but it got all the way to failing credit card authorization. Disgusting. Why do they think they can legally resell my work!?)
I guess it's an assumption that if you try to buy it from AP, then you have already concluded that the text is copyrighted by AP. I doubt they have instant access to everything they've ever written...