One part of the problem may be that far too many people are cleared to handle sensitive material. So many that the government cannot adequately investigate their backgrounds and their character. So many that secrets aren't really secret any longer.
As John Bacon and William M. Welch report in USA Today:
... more than 4.9 million people have some sort of government security clearance. About 1.4 million of those lay claim to "top secret" clearance.
Which seems like an awful lot. So many that bureaucratic confusions, fumbles and missteps would be inevitable. And, indeed:
A Government Accountability Office report in July blasted the Office of the Director of National Intelligence for failing to provide uniform policies across government agencies to "determine eligibility for access to classified information." The office declined comment on the latest leak.
Whatever else we learn from the story of the leaks, it does seem to bolster the case against the government on grounds of bloat ( 5 million clearances?) and ineptitude.