Facebook's acquisition of WhatsApp in early 2014 raised all sorts of red flags for security and privacy interest groups. Facebook, then and to some extent now, isn't exactly the epitome of those two values. Over time, WhatsApp has tried to assuage fears by implementing features such as end-to-end encryption. Apparently, that may be futile after all. Forensic scientist Jonathan Zdziarski revealed that, while the app does encrypt the messages it stores, it doesn't actually completely delete them and its backups still leave users open to spying or law enforcement.