I completely understand why this upsets you so much, especially since someone you care about is capable of such behavior. And, no, it certainly doesn't seem fair, but there's not much you can do about his access to this material. The information is readily available in magazines and on the Internet (just look at THIS column).

Perhaps the best thing you can do is to express to him how you feel being manipulated in such a way. I hope that his relationship with you, as his friend, will help him to have some empathy for all of the other girls who might be affected by his less-than-honorable behavior.

I hope that doing your part will help you feel better.