During his Congressional hearing, Mark Zuckerberg reiterated that Facebook doesn’t have access to WhatsApp chats thanks to end-to-end encryption.
In fact, communication channels between the WhatsApp and Facebook iOS apps could be abused to leak data from the entire chat history.
The object of this article is not to claim that Facebook snoops on WhatsApp chats, but that end-to-end encryption is used by both WhatsApp and Facebook as a disingenuous and misleading argument to reassure the public.