How free would your speech be if it was recorded for posterity with no way of controlling it? Just something else to think about.
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.
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.