By “society”? That’s what NSFW labels are all about. Even the expression is a nonsense euphemism. (You’d think that any not work related websites would be “nsfw”.) Anything to do with the mechanics of human reproduction is taboo. In practice, that’s 90% depictions of feminine bodies.

Of course, there is more to it than that. For example, in Germany, until last year, it was illegal to “advertise” abortions. In practice, that meant that doctors were prosecuted for providing information on the web.