Among all the shock and awe reporting on Virginia Tech, I almost missed this revelation from ABC news that the federal government is keeping records of what prescription medications Americans are taking: 

Some news accounts have suggested that Cho had a history of antidepressant use, but senior federal officials tell ABC News that they can find no record of such medication in the government's files. This does not completely rule out prescription drug use, including samples from a physician, drugs obtained through illegal Internet sources, or a gap in the federal database, but the sources say theirs is a reasonably complete search.

 I don’t have time to do any research today.  So can somebody explain to me exactly when, and under whose authority, the federal government began keeping tabs on our private medical records?