Here's a summary:
A neuroscientist says social networking websites shorten attention-spans, encourage instant gratification and make young people more self-centred. That's it. No evidence is cited, or even suggested to exist. Here are a few quotes from the neuroscientist, as reported in the article:
Fear, wonderment, difficulty of seeing, and lack of knowledge - not exactly the soundest basis for such conclusions, is it?
"My fear is that these technologies are infantilising the brain..."
"I often wonder whether real conversation in real time may eventually give way to these sanitised and easier screen dialogues..."
"It is hard to see how living this way on a daily basis will not result in brains, or rather minds, different from those of previous generations..."
"Of course, we do not know whether the current increase in autism is due more to increased awareness and diagnosis of autism, or whether it can - if there is a true increase - be in any way linked to an increased prevalence among people of spending time in screen relationships."
Susan Greenfield is a respected scientist, but the Mail's article gives the impression that her warning is nothing more than unsubstantiated opinion.
(via Derren Brown Blog)
Ben Goldacre appeared with Aric Sigman on BBC Newsnight the same day, in a segment also featuring recorded sound-bites from Susan Greenfield. Her statements are indeed unfounded - she admits as much. Watch the Newsnight segment on YouTube:
...and there was a follow-up on this morning's Today Programme, with Colin Blakemore injecting a modicum of common sense into the whole affair (thereby backing up Ben Goldacre's position):