Except they won't do the same job. Not all are like this, but after the CIO of my firm blocked MySpace and Facebook, young'uns actually called the help desk to report it as a problem.

As a general rule (though not all inclusive) you just don't get the productivity out of the workers fresh out of college, not even close. They don't have the same mindset as the 20/40/60 crowd. They come in when they feel like it, talk endlessly on their phone or cell phone, and take long lunches on the regular. This is definitely a case where you get what you pay for, almost exactly. The youngster will be cheaper, but less productive, and will lack the corporate knowledge of that 20/40/60 that you kicked to the curb. They'll also leave when things don't go their way.