The British government quickly weighed in to dismiss that claim, but the argument is still on over how time online might affect young minds.
CBS News correspondent Richard Roth took a closer look at the social networking controversy from London.
With millions frequenting Internet social networking sites, including Twitter, bebo and Facebook, the controversy was launched when a British scientist wondered out loud whether all that time online could be changing how the brain functions, shortening attention span, even contributing to autism.
Though she raised it in a House of Lords debate, Professor Susan Greenfield says her question was more speculative than scientific.
"Perhaps given the brain is so impressionable, that screen life is mandating that more infantilized lifestyle. Now this is based on a little bit of neuroscience, observations, a bit of clinical evidence, there is no one single or conclusive killer fact," Greenfield said.
One fact any teen will admit is that the Internet is an irresistible attraction.
"I'm addicted to Facebook. I go on it every single night," said a teen in London.
But the science jury is still out on whether there is a long-term effect. The question that should be asked is what the risk may be in missing out what time online has replaced.
"No study has ever found that extensive use of Internet social networks permanently damages the brain. But we have to ask the question, 'What happens to young people when they spend hours and hours with the computer? Are they getting outdoors? Are they exercising? Are they learning to talk to each other face to face?'" said Gary Small, professor of Psychology at UCLA.
The sort of questions raised more than two generations ago, when we started to watch TV.