Several of these Banks are only releasing a certain number of homes onto the market each month. They do not list or try to sell all the homes they own at once. This is because they fear if all the Bank owned properties come on the market now it will cause a glut and depress the prices even more.
You can walk around the outside of this house; sometimes they have signs on the outside saying who to call about information for the house. I would recommend you get together with a experienced buyers agent to handle your home search. Even if you wind up buying this house, you need a agent that represents your best interest and will get you the best price. The seller pays the buyers agent so why not use someone who can do the research and give you excellent advice.
If i can be of any further help.