Nine years after the terrorist attacks of 2001, the United States is assembling a vast domestic intelligence apparatus to collect information about Americans, using the FBI, local police, state homeland security offices and military criminal investigators. The system, by far the largest and most technologically sophisticated in the nation's history, collects, stores and analyzes information about thousands of U.S. citizens and residents, many of whom have not been accused of any wrongdoing. The months-long investigation [by The Washington Post], based on nearly 100 interviews and 1,000 documents, found that: * Technologies and techniques honed for use on the battlefields of Iraq and Afghanistan have migrated into the hands of law enforcement agencies in America. * The FBI is building a database with the names and certain personal information, such as employment history, of thousands of U.S. citizens and residents whom a local police officer or a fellow citizen believed to be acting suspiciously. * Law enforcement agencies have hired as trainers self-described experts whose extremist views on Islam and terrorism are considered inaccurate and counterproductive by the FBI and U.S. intelligence agencies. * The Department of Homeland Security sends its state and local partners intelligence reports with little meaningful guidance, and state reports have sometimes inappropriately reported on lawful meetings.