Rumors spread negativity about other people. They're vile.
Rumors have momentum, and once in motion their natural state is to remain in motion. I get an immense amount of satisfaction from killing rumors. You know, hearing one, and just letting that momentum die and the information stop there. Knowing that there are tens, hundreds, even thousands of people who will never hear it, because it stopped with you. Sure it may still spread… you cannot control what others say. But you can control what you say.
It's good to speak with restraint… to not just blurt out whatever incoherent thought is running through your mind at any given moment.