If you've ever chanced upon pictures of an old flame on Facebook, you'll know how easy it is to get in touch. But what if those succumbing to online temptations are already married or in a long-term relationship?
It's a scenario that is becoming increasingly common, according to divorce lawyers, many of whom now routinely demand access to their clients' Facebook pages before agreeing to take on a case. And when relationships break down, the evidence is there online for all to see.
"We're coming across it more and more," said Steven Kimmons, a clinical psychologist and marriage counsellor at a Chicago university. "One spouse connects online with someone they knew from school. The person is emotionally available and they start communicating through Facebook."
Research by the American Academy of Matrimonial Lawyers found that two-thirds of lawyers reported using Facebook as the "primary source" of evidence in divorce proceedings and Divorce-Online, a British-based do-it-yourself divorce site, has reported that the word "Facebook" appeared in about one in five of the cases it was handling.
Photographs posted by friends or colleagues on their own pages provide particularly juicy material, while stories abound of divorcing husbands or wives being tripped up by online "oversharing" or untruths – like the man who declared his single, childless status on Match.com while seeking primary custody of those apparently non-existent children.
"It would be ridiculous to say that Facebook is responsible for divorce," Mark Keenan, founder and director of Divorce-Online, told MyDaily: "Facebook doesn't cause divorce: people cause divorce. What it has done is made it easier for people who want to cheat on their partners to do so. And, potentially, to get found out if they end up in court."