Hacked iphone. Any advice on what to do?

[Pedro83]

might it not have been the numerous microphones that iPhone has simply listening in, I’ve had similar experiences without using WhatsApp?

Maybe. Weren't people compensated as a result of apple doing this? -- I recall reading about it. Im a pixel user, no doubt same caveats apply....

 

[Sue Pertwee-Tyr]

Here is a legal GDPR-compliance view of Whatsapp (link). If you run any business that holds customer data you really do need to understand this sort of thing. Annoying, but it is just the way things are now.

That analysis is a bit shallow. It is only valid if it assumes the whole data from your contacts is harvested. If all that WhatsApp collects is telephone numbers, to match against numbers in its database (which is my understanding) then what that article says starts coming apart at the seams.