Google has built a clever warning system that tells smartphone users if their screen has been snooped at by obviously an uninvited “witness”.
Dubbed the Electronic Screen Protector, it uses technology to spot the snooper and flashes up a live video of them.
To embarrass the person and alert the user, the offender has a rainbow stream from their mouth as a message pops up which says: “Stranger is looking alert”.
Google researchers See Jung Ryu and Florian Schroff say the app was built to protect smartphone users “from onlookers in a crowded space such as the subway or elevator”.
But some critics say the fact that the phone’s front camera must be on for the app to work could raise security questions in itself.
The app is expected to be revealed at a conference in California, which starts on Monday.