One way that we technical folk can help prevent this is by purchasing a domain that we can call our own and then host a website that's very clear: "If my image or voice is used in a piece of digital media that is not linked here from this domain, it was not produced by me."
That, and cryptographic materials being used to sign stuff too.
I think that's possibly the best we can hope for from a technical perspective as well as waiting for the legal system to catch up.