You might be surprised how much the law lags at criminalizing morally reprehensible acts enabled by technology, like revenge porn.

I can't speak to other countries specifics, but in the US the most effective avenue currently appears to be copyright claims. That's a civil proceeding, so the jilted ex is only on the hook for financial penalties.

http://www.criminaldefenselawyer.com/resources/revenge-porn-...