You are right, this was a huge topic in the 1980's. It was one of the pillars of my teenage faith. If demons were so active in the world, then Jehovah must be real too.
The strange thing is that no one seems to even remember. I remember my mother saying my sister was levitated at a worldly party that she went to and there was a photo. Neither of them recall it. My best friend used to have knives thrown by demons above his head whilst he was in bed. He is now an atheist and said it never really happened. I wonder how much was people jumping on the bandwagon and exaggerating what really went on, just because it was something that was supposed to be happening.