A new study has revealed that as many as half of Facebook users - that's more than half a billion- are risking psychological damage from using the site to spy on former flames.
People find it hard to stop themselves keeping tabs on their ex-partners when their face pops up on the Facebook timeline, explained the study conducted at Brunel University.
Clicking on his profile to see him with his arms around another woman, or even simply enjoying an evening out with mutual friends can feel like a knife through the heart, it said.
Before the advent of Twitter and Facebook, or photo-sharing sites like Instagram.
Earlier spying on a former lover required a serious dedication, gathering information from friends, or hanging hopefully around their favourite haunts.
But with the advent of Twitter and Facebook, or photo-sharing sites like Instagram, you can keep up continual surveillance, checking where they are, what they're doing and who they are with - and it makes it all the more difficult to move on, says psychologist Dr Tara Marshall, who led the study.
In her survey, Dr Marshall and her team found that those who remained Facebook 'friends' with an ex experience more distress and took longer to move on compared with those who immediately clicked 'unfriend'.
"Overall, these findings suggest that exposure to an ex-partner through Facebook may obstruct the process of healing after a relationship," the Daily Mail quoted her as saying.