As far as funding goes, I heard an interesting program[1] recently on History Counts[2] which claimed that the CIA was covertly funding its own operations in Southeast Asia through drug trafficking.[3][4]

In comparison, the wholesale spy program that's been in the news recently has far more potential for profit through economic espionage, blackmail, and various types of political manipulation. It could easily be self-financing if the information gathered through it was exploited.

This program is a proverbial goose laying golden eggs for the government. I really can not imagine them closing it down over a bit of bad press (which will probably die down and blow over as soon as the next big scandal hits).

[1] - http://www.radio4all.net/index.php/program/30027

[2] - http://www.radio4all.net/index.php/series/History+Counts

[3] - A small excerpt:

Q: "Through the drug profits, were these operations essentially self-financing?"

A: "Everything in the Far East was self-financing"

Q: "And they were off the books, so there was no public record or accounting?"

A: "Of course I'm speculating here, because no one has done me the favor of showing me the CIA's books, but I think when we get to the scale of a 35,000 man army in Laos in the 1960's -- Congress found out about that and held hearings in to it and were complaining they've never been told about it, so I assume all of that was financed by the drug traffic than it was -- whatever input there was from the CIA's legitimate budget was minimal compared to what was happening... that was built up continuously from the 1950's"

[4] - I'm not saying I believe in this particular conspiracy theory. I've really not looked in to this subject beyond this one History Counts show. But I could see something like it happening, and the current mood is one where such conspiracy theories are starting to look more probable than usual.