Show Us the Data: The Most Wanted Government Documents

This department, created under George W. Bush, serves as a "security" branch, but all work is done by the private sector - where is the legal precedent/ rational for subcontracting the national security operations of the US government? This is our security at stake, and it has become a for-profit industry whose survival depends on the perpetuation of the "war on terror"; what is the public knowledge of their activities? Where can one find anything about who is "providing security" for the US, and how they obtained that contract? What, if any, review/oversight process is in place for the allocation/necessity of contracts?