Books are not harmful. (Human Events Online list of the most harmful books written)
What's more harmful or dangerous is people who are afraid to let others read ideas that are opposed to theirs.
The list is full of the usual suspects. Everything you think will be there, is.
I'm not at all surprised that the Kinsey Report made the list. Everyone knows that sex, when not used for procreation and performed between a man and woman in the missionary position, is DANGEROUS! Sex leads to pleasure! Pleasure leads to the dark side!
Look at the runner ups. Silent Spring. Coming of Age in Samoa. Introduction to Psychoanalysis. Unsafe at Any Speed. I'm starting to understand Human Events Online's meaning of DANGEROUS.
But my favorite honorable mention is Origin of Species. Science is DANGEROUS! Evolution is scary!
Do not attempt to think for yourselves. Do not attempt to learn about views apart from your own. Do not attempt to see two sides of a story. Do not attempt understand how other people think. These things are EVIL. And any books about them are HARMFUL.
Books are not dangerous. People with narrow views who fear people learning about things outside that view are incredibly harmful.