Wow, Vienna scientists received the complete WhatsApp member directory, containing 3.5 billion user entries. Yes, it’s just the directory, no messages, but the whole directory was available online - totally unprotected.
Any more reasons for not using WhatsApp required
heise.de/en/news/3-5-Billion-A…
3.5 Billion Accounts: Complete WhatsApp Directory Retrieved and Evaluated
Vienna researchers retrieved all WhatsApp numbers. The 3.5 billion profiles represent the largest data leak in history—and it's worse than you might think.Daniel AJ Sokolov (heise online)