I was under the impression the FBI and CIA are separate agencies from the IRS, i.e., they can't just secretly tell the IRS to audit someone.

Trying to dredge up the articles; I believe that the CEO of a high-tech company was heavily investigated by the IRS after he threatened to make an NSL public.

In the past, the IRS has definitely been used as a tool to apply pressure. It's not supposed to happen, but it does.

> Trying to dredge up the articles; I believe that the CEO of a high-tech company was heavily investigated by the IRS after he threatened to make an NSL public.

Joseph Nacchio[1], CEO of Quest?

His case[2] is a clear warning shot that if you don't play ball with the spooks, the government has no problem throwing the hammer at you.

[1] https://en.wikipedia.org/wiki/Joseph_Nacchio#Career

[2] http://www.businessinsider.com/the-story-of-joseph-nacchio-a...

Yup, that's the guy.

They will use whatever powers they have to coerce companies (or individuals) into cooperating, including with holding contracts or causing regulatory headaches.