So you've quit Facebook, deleted the app from your phone, cleared every cookie out of your browser history, asked the company to delete all your data and endured the mandatory one-month cooling-off period. Finally you have completely opted out of its data-gathering web.

Or so you thought. Even if you don't use Facebook, you probably use WhatsApp – the privacy-conscious citizen's chat app of choice, with all messages fully encrypted. Perhaps you are part of the wave of people switching from public social media to private messaging. Sure, you might know that WhatsApp is owned by Facebook, but you also know that the two apps have historically been kept separate.

Now that is starting to change. Earlier this month, news broke that WhatsApp (along with Instagram) will be unsubtly rebranded to "WhatsApp From Facebook". The week before, eagle-eyed beta testers spotted a new function allowing WhatsApp users to share posts to Facebook or Instagram.

And, of course, Facebook will soon integrate the messaging functions of WhatsApp, Instagram and Facebook Messenger into one unified and encrypted system behind the scenes – potentially spelling the end of the firewall between the blue app and the green.

Facebook has also said that adverts will appear in WhatsApp from 2020. They'll take up your whole screen and will appear in between WhatsApp statuses – temporary broadcasts similar to Instagram stories or Snapchat messages.