At first glance there seems to be more more malicious uses than good ones with voice. Yes, hearing someone dear to me say things he/she never said maybe comforting. Anything else? Maybe some movies with the deceased actor's voice? But what if someone who wants to hurt me sends me files (or phone calls) from the deceased person saying horrible things like: - "I am still alive but left as I was tired of you" - "oh Jan,…
We can barely trust pictures anymore either. It seems we'll be going back to judging the likelihood of one's actions based on one's reputation, for better or for worse. There soon won't be such a thing as unreasonable doubt.
And public/private key validation may become invaluable.