Jews, witches, heretics and homosexuals have all been accused of wanting to harm young people. One of the only ways to justify horrific brutality against harmless groups of people is to lie about them coming to defile your kids. This has been well-documented.
The scapegoater never provides conclusive evidence of this harm – public pronouncements repeated in the mainstream media seems to do the job well enough. The burden of proof for establishing inherent harmfulness should be on the people pointing the fingers, and not the people being accused of being inherently harmful having to prove this is not the case.