Adulterers better act extra careful when using WhatsApp to pull their shenanigans. It turns out the Facebook-owned messenger suffers from a vulnerability that can be exploited to spy on your sleeping patterns – and find out precisely at what time you go to sleep and wake up. What is particularly disturbing is that practically anybody with a little technical understanding and a spare laptop can abuse this flaw. The issue stems from the WhatsApp’s last seen and online status features which make it possible to continuously check up on your contacts for the last time they were online. The worst part, though, is that there is nothing you can do to stop attackers from monitoring your activity. While WhatsApp has an option to show your last seen status to everyone , only your contacts , or no one , there is no way to disable the online status feature which reveals you’re actively using the service. This might seem ra...