But the problem arises, I think, is when they say they can't read them: "WhatsApp's end-to-end encryption is used when you chat with another person using WhatsApp Messenger. End-to-end encryption ensures only you and the person you're communicating with can read or listen to what is sent, and nobody in between, not even WhatsApp."
https://faq.whatsapp.com/general/security-and-privacy/end-to...