How this works technically is a mystery to me, because normally the verification process for such a telephone number is very secure and if someone uses Whatsapp web, I can see the list of connected devices and deactivate accredited devices. In my case, however, there was NO conspicuous entry in the list. I still deactivated everything. However, the problem persists.
What options are there to protect WhatsApp against such piracy? Does anyone know how these hijackings work technically?