In the light of the WA panic reaction to Signal becoming the most downloaded app on both Android and iPhone stores, I thought I'd set the record straight.
Yep, your chats and attachments, pics etc remain secure, nobody can see them and nobody will mine the words or the contents of the pictures.
On the other hand metadata, such as the businesses you talked to on Whatsapp, the number of contacts you have in your phone, the location in which chats were initiated or responded to, the metadata of pictures including the date, time and location they were taken, are all fair game.
This data will be grabbed, correlated, massaged and sold to vendors who are clamouring to start targeting sales to WA users.
Then we have to remember that WA is a Farcebook company. You know the data monsters who think that the fact you are on their system means you are their plaything.
Given how Facebook has used users' personal data in the past – the social network was caught manipulating users' emotions back in 2014 by bombarding some people's News Feed with an onslaught of upsetting posts so that Facebook's on-staff data scientist could see whether the website could materially impact someone's emotions in real-life
There will always be those who don't care. I care. You can't find me on google unless you know my main email address. Colleagues who want to hook up on LinkedIn, where I do share my data to all, often need my email address to find me.
I must admit, I do wonder if being on WA has increased the number of nuisance calls I get from either sales or illegal stuff like the HMRC fraud calls. I seem to recall that prior to WA, I had one or two a year. Since I registered that has increased exponentially. It is not until you realise that WA was already sharing data with FB (Apple outed them on that), that you begin to wonder.