If you weren't sure that the Occupy Wall Street folks had a real complaint, these facts should dispel any doubts.
Since 1979, the richest 1% of U.S Households saw their after tax incomes increase by 275%.
In that same period, the incomes of the 60% of the households that make up the middle class had an after tax income increase of 39%
While the bottom 20% of all households had an increase of 18%.
Source of these numbers? The Congressional Budget Office (CBO)