And then there is also the distinction between maliciously defaming someone, and passing on things you heard in good faith. No, there isn't, morally or legally

And then there is also the distinction between maliciously defaming someone, and passing on things you heard in good faith. No, there isn't, morally or legally. If you make defamatory statements, it doesn't matter whether you made them up or simply heard someone else say them and are just passing them along. It's still defamatory, and that's how US law treats such statements (and how it has always treated defamatory statements). Truth is the defense to a defamation lawsuit, not "a little bird told me." TLDR: unless you actually know that Bob is a pedo because you witnessed his crimes or he has been convicted, don't defame Bob.