Creating a database of phone numbers, profile pictures and status information of almost all users of WhatsApp turns out to be very easy . The user doesn’t even have to be added to your contacts. This should raise at least some privacy concerns and hopefully a lot more. Let me explain how it works.
A few years ago WhatsApp made it possible to use WhatsApp in your web browser. That is good for user experience because composing a message on your keyboard is a lot easier than using those tiny touch screen buttons. It also makes copying/pasting and adding attachments easier. So much for the good news. The bad news is that it’s technically possible to use the WhatsApp Web interface to create a huge database of all possible WhatsApp users. There’s only a small group of users not affected: the users who have changed their privacy settings. Unfortunately, most users don’t change those privacy settings and WhatsApp doesn’t encourage it very much. These facts open up the possibility of collecting huge amounts of interesting data which i’m going to show you now.