Ask HN: If sharing music is illegal, how am I able to share music on WhatsApp?

I know WhatsApp's intention is not to distribute copyrighted music but it does allow sharing of copyrighted music with peers. one might argue that it is "User Generated Content" but its still copyrighted material which the user has no right to share. obviously, WhatsApp(coughfb) won't face any legal actions cause its not explicitly telling people to share copyrighted material but, it never the less is illegal right? PS. not sure about iOS, but it definitely allows sharing music on android.

So the question is if an app explicitly allowed people to send music like WhatsApp allows will it not face any legal issues?