I think that the discussion here might get a bit two dimensional; mature slashdotters who use the internet a lot and know it's beneficial arguing against a woman who black-boxes the internet by presuming that badass teens who use the internet in ways she can't imagine are affected by it, somehow, and thus it serves as the reason for any malady she can think of since she has no causation or even much correlation in her arguments.
For those of us with partners, friends and family and not in their teens, it's pretty obvious that while us nerds delve fully into the fringes technology which has been developing rapidly, everyone else is using technology the same way. From the invention of the telephone to the mobile, the main reason people are on the net is to talk to one another - which isn't a sea change at all, since people always do it face to face too. And now people are using it as their diary, and encyclopedia. Not game changers either, for the brain. Just quicker.
I think xkcd 973 is appropriate. Teens are badass because they're teens. Not because of MTV or the Tubes.