but the link isn't content. it would be like putting up a picture of a brown paper bag, with a note next to it that said "behind this brown paper bag is a drawing of two seven year olds having sex."

there would be no objectionable material, because all you'd actually be able to see would be the brown paper bag, and the factual statement of such a drawing existing, in and of itself, is not graphic and therefore not impermissible content.