'Watching eyes' poster reduces bicycle thefts
24 April 2013 Last updated at 18:51 BST
A poster above a bike rack, showing staring eyes and the message "we are watching you", has succeeded in reducing thefts by two-thirds.
Researchers at Newcastle University put the posters up in some areas where bikes were parked, but not in others.
While the thefts dropped in locations with posters, they rose by two-thirds at the racks without.
Danny Savage reports.