Darkkness...don't Succubus and incubus draw energy from people? Hense the whole seduction while sleeping thing?
Unless everything I have ever read about them is a complete lie...they would infact interact with people.
That being said, what the poster said isn't a lie. He could be misinformed as to what it is, but that doesn't make it a lie. And at no point did anyone say they were "evil".