I know someone who looked into the fake propaganda spread around social networks in Myanmar (WhatsApp is essentially not used there, but Facebook and Viber are the big ones). It turned out it was virtually impossible to trace the origin of messages because most people were copy/pasting messages instead of forwarding them. Which makes me wonder how much of an impact is actually expected of this. The cynic in me worries that it may be a way for the platform to wash its hands...