WhatsApp is trialling a new feature on some Android handsets that allows you to restrict screengrabs of your personal chats. However, there's a flaw: it only stops screenshots being taken on your own phone.

That means other members of the chat group can take screengrabs on their devices, which somewhat negates the purpose of the security option.

First discovered by WABetaInfo, the website that reports on changes in beta versions of the Android app each time it is updated, the blocking of screenshots is enabled within the authentication section of settings.

When fingerprint unlocking is switched on, the phone will block screengrabs of any of your chats. But strangely, it doesn't block others.

Why would you want to block yourself taking screenshots when everybody else in a group can? It makes no sense, as WABetaInfo illustrated in a subsequent tweet.

In addition, the feature in the beta build is linked with fingerprint unlocking, so you cannot secure your WhatsApp application behind biometric authentication without preventing yourself from also taking grabs.

Bonkers.

We suspect this feature will either be removed or changed somewhat before a public release of the update.

At present, it is only available to those who signed up to the Google Play Beta Program. Thankfully.