A law firm specializing in divorce says nearly one in five cases they are working on involved a person's activity on Facebook.
Mark Keenan, Managing Director of Divorce-Online, told the UK's Telegraph
he was really surprised to see 20 percent of all the petitions containing references to Facebook.
"The most common reason seemed to be people having inappropriate sexual chats with people they were not supposed to," he said.
The most cited evidence, he added, are flirty emails and messages posted on "walls."
Many people even pay technology firms to develop software that can allow them to spy on their spouses' online activity.
In the UK, approximately 14 million people log-in to social networking sites such as Facebook and Friends Reunited regularly. The increased activity and socializing with friends sometimes sparks flames with old lovers.
While the divorce rate in the UK
has fallen in recent years, Keenan said it would climb in 2010 due to the recession.