Is Facebook dangerous?

"Social networking websites are causing alarming changes in the brains of young users, an eminent scientist has warned."

"Sites such as Facebook, Twitter and Bebo are said to shorten attention spans, encourage instant gratification and make young people more self-centred."

The claims from neuroscientist Susan Greenfield will make disturbing reading for the millions whose social lives depend on logging on to their favorite websites each day.

What do you think?