Paedophile of course originally meant, someone who really loves and cares for children. The correct word for someone who sexually preys on children, is a paedorast or paederast, but when the inter-net was new and some of them started to form porn and exploitation groups, they of course did not like that name, so they called themselves paedophiles. So that when the alarm first went up it was about self styled paedophiles, and the name stuck, so that the modern use of paedophile is a slang term as well.

This is not very important as a part of modern history, though the abuse of a perfectly good word is not a good thing. But it is worth remembering if you encounter the word in older books, that to writers before the late twentieth century it had exactly the opposite meaning to what it commonly does today.