Banning porn sounds great until you realize it means you lose HBO's The Wire, House of Cards and a long list of other iconic media because they contain scenes of sex acts and naked women in strip clubs.
There is no objective standard to distinguish them from "bad" porn.
It's legal speech. It's being destroyed because Google doesn't like the content. In this context, there's no particular difference between video and a book.
There is no objective standard to distinguish them from "bad" porn.