Flirtations on the social networking site are increasingly becoming a major factor in marriage breakdowns. Family lawyers have revealed that the problem has become so great that almost every divorce they have dealt with in the past year has involved the website.
One expert said she had dealt with 30 cases in the last nine months and Facebook had been implicated in them all. Whilst another online law company said one in five of their divorce petitions in the past year contain references to Facebook.
Emma Patel, the head of family law at Hart Scales and Hodges Solicitors, said the site acted like a "virtual third party" in splits.
"Facebook is being blamed for an increasing number of marital breakdowns, and it is quite remarkable that all the petitions that I have seen here since May have cited Facebook one way or another," the Telegraph quoted her, as saying.
"Its huge popularity as well as the lure of sites like Second Life, Illicit Encounters and Friends Reunited are tempting couples to cheat on each other. "Suspicious spouses have used these to spy and find evidence of flirting and even affairs, which have then led to break-ups," she said.
She said that many of divorces came after partners found "flirty messages" on the Facebook wall of their partner-and also "inappropriate suggestive chats" which spouse's can see.
The lawyer said that she urged all clients to "stay off" Facebook during divorce proceedings-as it could throw a spanner in the works of it going smoothly-especially if they post photos of new lovers. She said: "They feel compelled to share their feelings online, and, in some cases, they not only express their stress, but also make inflammatory accusations against their partner."
James Wrigley, of Hackney, east London, said, "My girlfriend left me after finding out I had been sending Facebook messages to a girl at work. "She got my password and read the messages and that was the end of that-four years together down the drain, but at least we hadn't got married."
Meanwhile, a spokesman for Facebook said it was "tosh" that Facebook could ruin a relationship. "It is like blaming your mobile phone or your emails. "Does being on Facebook force you to do something-absolutely not I would say," he said.
This is definitely not something Mark Zuckerberg had in mind when he built Facebook.