...The IRS has failed twice to modernize its system, in the 1970’s when taxpayer privacy issues surfaced and in the mid-1990’s when the IRS spent ten years and $2 billion on the project and had little to show for it. The current project launched in 1999 with a budget of $8 billion. The project is late and over-budget; problems have been well publicized after the release of the IRS Oversight Board investigation...
http://www.kellogg.northwestern.edu/student/courses/tech914/...
AFAIK, the IRS dropped $10 Billion in IT money in just over a decade with little to nothing to show for it.
I used to joke around and say heck, they could have paid me 2 Billion and I would have also provided them nothing, but look at the money they would have saved!
So NSA, which is fairly young, stays out of the political eye (until recently), and small? They do some really cool stuff. But the older, more controversial agencies, covering things like immigration, defense, taxes, health, and so on? Not good.