From New Scientist.

IN CROWDED cafes and on public transport, it's easy for people to eyeball the info on your laptop or smartphone screen. Now Sony Ericsson is patenting an answer.

Some privacy settings already let you hit a button to blank your screen when you sense a shoulder surfer is lurking. But we are often too engrossed in our work to notice such interlopers, say inventors Martin Ek and Bo Larsson.

As many netbooks and laptops now have webcams, and some smartphones have front-facing cameras, the pair have developed software that can tell when more than one face is in front of the device – and blanks the screen till they're gone (bit.ly/9fp5Gj).

They suggest certain friends could be allowed to read your screen if facial recognition software is used to exempt them from the blanking mechanism.