WhatsApp integrated¹ Signal's secure messaging protocol. Since then, at least one government was unable to compel² the company to produce unencrypted messages from users under investigation.
Given the popularity of WhatsApp, I think its safe to say a lot of people are now using a relatively secure messaging protocol.
¹ https://whispersystems.org/blog/whatsapp-complete/
² https://www.forbes.com/sites/parmyolson/2016/05/03/whatsapp-...