Masturbation is not harmful, I don't care how young the person in question is. Things become safer when they're condoned and educated-about.

My view on kinkiness and the internet is that the internet mostly makes it easier for people to discover their kinks, and those who already know about them realize they don't have to settle for "vanilla sex."

Whether something is taboo has nothing to do with whether they are actually immoral. Things that are immoral cause harm to animals (human and otherwise). If something doesn't fit that bill, it can't be considered immoral.