Allow me to tell you a story.
There once was a guy, and he had a girlfriend. And he had a "mistress" on the side. Most of us knew. When he left the girlfriend, he didn't start being truly open about the mistress, but started a relationship with another girlfriend. Well, this girlfriend started talking shit about the "mistress" -- tramp, whore, etc. But also just generally mean and bad things. And we were like, no -- I mean, yeah, about the tramp part, that's why he went to her. Because he wasn't getting what he needed from the first girlfriend. But that doesn't make her a bad person.
Well, I have since stopped being friend with boyfriend and girlfriend, and am now pretty good friends with "mistress". Do you know what? She's a really nice person. And no, I'm not sleeping with her. She got a little messed up by that (sort of like sleeping with a married man), but she's over it (happily married now, herself -- to someone else).
Here's the funny part -- I was surprised to find out she was a nice person. Even though I didn't believe gf#2, she still repeated it enough times that I began to believe it, subconsciously.
So, moral of the story? If you repeat something enough times, people will believe it. If you repeat something enough times -- even if it isn't true -- people will believe it. If you repeat something enough times, with enough emphasis, people will believe it.
Goebel knew. Hitler knew. It's a war of words, and it has to be fought. The unfortunate part is -- no-one wins.