Wilson points out that the EPA has a much better track record forcing compliance with environmental regulations with private companies than it does with other government agencies, particularly the defense department. This appears to be a general principle in the government: the government finds it easier to compel private entities to follow regulations than it does other federal agencies. Wilson (in his book "Bureaucracy") documents the same phenomena with OSHA as well.
Now we see the principle at work with the Obama Justice Department, which has told its employees not to cooperate with the Commission on Civil Rights' probe of the Black Panthers apparent intimidation of voters in the 2008 election. There are lots of things one could say about this, but one aspect I think is easily overlooked is the general problem with a larger government. We create government to protect us from powerful organizations and entities, but as more organizations and entities are absorbed into the government, the government's ability to protect us actually weakens. The Federal government is (arguably) good at protecting us from the private sector, not so good at protecting us from other branches of the federal government itself. Something to think about.