17-year old security researcher, Indrajeet Bhuyan, discovered this problem. The problem occurred due to the new web version and is said to be a result of the phone app not being synced properly with the new web interface.

Bhuyan also discovered another WhatsApp security bug in the web version. The web app shows photos that have been deleted. On your phone, you will notice that the photos get blurred once you delete them, but look like the web saves them indefinitely.

This means the web version introduced last month still does not follow all the security measures taken for the mobile version.

One of the best WhatsApp security tip is to protect the app with a password or PIN. WhatsApp itself does not offer such a function, but there are third-party apps that do.

You can restrict or disable who sees your 'last seen' time in WhatsApp's 'Profile,' 'Privacy' menu, in iOS, Android or Blackberry. However, you need to be aware that if you turn it off, you won't be able to see other users' 'last seen' times either.

Anything offering a free subscription, claiming to be from WhatsApp or encouraging you to follow links to safeguard your account is definitely a scam and not to be trusted.

WhatsApp offers users effective and simple security tips to keep control of your account if your phone is stolen or lost. Locking your SIM card through your network provider, WhatsApp recommends that you immediately activate WhatsApp with the same phone number on a different phone, with a replacement SIM.

Don't send personal information if you can possibly avoid it - phone numbers, address, email addresses - and never send your social security, bank, credit card, passport or other identification details.