When some wired Singaporeans break up with their partners, they find a new love - snooping on those exes via Facebook.

Keeping track of past girlfriends and boyfriends on the social networking site has become a passion for former flames, going by an informal check by LifeStyle.

Twenty Facebook users aged between 20 and 35 were quizzed and most said they have former romantic partners on their friends list.

Ten users said they actively keep tabs on their exes for reasons ranging from nosiness to nostalgia.

Take Ms T. Toh (most first names have been withheld on request), for example. For a month after breaking up with her boyfriend in February, the lovelorn 21-year-old logged on to Facebook for hours every day, tracking him via the updates he posted.

'I really wanted to see what he was doing, who he was hanging out with and find out why he didn't want to meet me,' says the Singapore Institute of Management student.

But eventually, 'it hurt too much', she tells LifeStyle. 'So I checked his Facebook profile only when pictures of him with girls popped up.'

Facebook has made it easier than ever before to snoop on past or current romantic interests. No wonder she could not resist putting herself through the ordeal.

Users receive a constant stream of text and photo updates from their friends via a 'newsfeed' page that appears when users log on.

The curious can spy to their hearts' content without the other party knowing they are doing so, unless they post a comment.

Another who succumbed to this phenomenon dubbed 'Facestalking' is Mr J. L. Loh, a 20-year-old computer engineering student. He says: 'Just after we broke up, I woul dedicate one browser tab to my ex-girlfriend and leave it on the whole day.'

He now has a new girlfriend but admits that he still checks his former partner's profile for 'any potential scandals or gossip or cute photos'.

Obsessing over exes is a real danger for the heartbroken, as Dr Adrian Wang, a consultant psychiatrist at Gleneagles Medical Centre, can attest to.

He has seen two cases of 'Facestalking' this year.

One involved a man in his mid-20s who could not stop checking on his ex-girlfriend via her Facebook profile.

Dr Wang says: 'He would check on her activities and photos and make assumptions.

'He'd become angry or jealous, feel unfairly treated and ask himself why she is so happy and partying around with friends.'

But while lurking online did the patient no good at all, he suffered just as much when the ex-girlfriend removed him from her friends list, the psychiatrist says.

Psychologist Daniel Koh of Insights Mind Centre notes: 'It becomes a cycle. A jealous person looks for information that will reinforce his jealousy, which causes him to look for more.'

This has had extreme consequences in at least one case. In Britain, 31-year-old Brian Lewis is on trial for allegedly killing his girlfriend after she set her Facebook status to 'single'.

Yet, deleting an ex from your Facebook friends list may not be enough to protect you from information that can cause jealousy or hurt.

Soon after splitting with her boyfriend, marketing executive Shana N., 25, saw photos of him with another girl. It was not her ex who posted the updates - they came to her attention via the other woman, who was also in her Facebook network.

Upset, she became obsessed with checking his profile every five minutes, until about a month later when she realised it was silly.

Facebook can make it more difficult for people to move on, says Dr Wang.

'Both parties often share a common circle of friends and the person who has been dumped has to deal with seeing the other person in friends' photos,' he says. 'This can provoke feelings of sadness, anger and jealousy.'

Civil servant Alexis Wong realised this when she broke up with a boyfriend two months ago. To stop herself from turning into a voyeur, the 25-year-old deleted him from her friends list. She also asked her friends to take him off theirs.

Mr Koh and Dr Wang agreed that sometimes a person may need to take such steps before they can move on. 'Just treat it as part of the break-up,' is Dr Wang's advice.

'Talk to a trusted person as well,' advises Mr Koh. 'It gives you a chance to express your hurt and pain and the support and reassurance can help you move on.'

In an interesting twist on modern relationships, it turned out that the man who broke up with Ms Toh earlier this year, 22-year-old A. Chew, also turned to Facebook for ex-checks.

The fellow SIM student told LifeStyle that it was hard to stop doing so, even when it hurt.

Of those cyber-snooping days, he recalls: 'Usually there was a highlight that aggravated me - like pictures of her with old boyfriends or other men.

'Although it may not be pleasant, you still want to see it.'

Sometimes, he even tried to dig up information on the men in the photos, although that was as far as it went, he said.

Ms Toh, meanwhile, turned to her mother after the break-up began affecting her physically. She recalls: 'I couldn't eat, I couldn't sleep. My mother made me eat and told me not to think too much.'

But it turns out that you cannot beat good, old-fashioned face-to-face contact.

By late June this year, Ms Toh and Mr Chew began communicating as friends again, meeting up to have heart-to-heart talks in which they worked out their problems.

Now, they have become a couple again. They no longer rely on Facebook to check up on each other, both told LifeStyle separately.

'There's no need now,' said Mr Chew. 'We're with each other most of the time anyway.'

This article was first published in The Sunday Times.