That is the charge by one British health official according to numerous reports. The claim is based on the argument that Facebook allows more people to meet up, thus more sexual relations.

“Data published by several British newspapers this week indicated that cases of syphilis had increased fourfold in Sunderland, Durham and Teesside - the areas of Britain where Facebook is most popular,” a Sydney Morning Herald report stated. “Professor Peter Kelly, director of public health in Teesside, told The Sun newspaper that 'social networking sites are making it easier for people to meet up for casual sex'."

“I don't get the names of people affected, just figures, and I saw that several of the people had met sexual partners through these sites,” he added.

Sounds like a stretch to me. That's like blaming banks that expand the number of branches for a rise in bank robberies.