If I want to control the distribution of my own speech I can do that now by asserting copyright.
No, you can't.
If you say something in public, and someone records with an iPhone and puts in on YouTube - you have no legal recourse on that matter.
Many other agents engage in repression of speech: we repress ourselves, so do parents, friends, communities, lawyers, contracts. We don't automatically regard repression of speech/expression as a bad thing, and in many cases we are glad for it.