Did the banks unjustly burden mortgaging home owners to stay afloat ?

Did wealthy well informed people take advantage of poor folks without access to all the facts, no brainer IMO. As we speak the large mortgage banks are not allowing all the foreclosed homes to go back on the soft real estate market. this manipulation of the housing market adds artificial value to every home in America, any person purchasing a home today will pay 30, 40% maybe more then the home is actually worth. Once all these foreclosed homes hit the market the value of all houses will plummet, which is necessary for the "free" market to right itself.