"Every day, just to keep up to date, that grey lump between your ears has to shovel ever bigger piles of infotainment — tottering jumbles of global-warming updates, web gossip, refugee crises, e-mails, fashion alerts, Twitters and advertisements. Now research suggests that we may have reached an historic point in human evolution, where the digital world we have created has begun to outpace our neurons’ processing abilities"

Too much stuff and too little hard drive space.

Too much stuff - very little of it of any great relevance is probably more the truth of it. Desensitization caused by too much input, leads to lack of discernment, mind-numbing inability to respond.

Someone sent me this youtube video about teenagers (which is a huge generalization), yet, obviously there are quite a number that possibly do fit this stereotype.
http://www.youtube.com/watch?v=gKaUL2mtAqA

Ouch! My fotolia hurts...