The relationship between government, the military, and technology has an incredibly rich and colored history. Sometimes, science is challenged and expanded by the needs of the people, as with the space race in the 1960's. However, technology can also be twisted into devastating weaponry, as evidenced by the atom bomb and its progeny.
I think that judging the agencies who use (and break) encryption is unwise - after all, I want the NSA to break the next Enigma code in the next big war, even if the government has swung too far to the fascist side of things.
As for technology as a double-edged sword, well, that's undeniably true, but the implication of using the word "sword" is a violent one. I prefer to think of technology, and science in general (esp. math!) as a natural resource. We can build computers with it; we can build 100 megaton bombs with it. In the end, the way we use technology is our testament to the ages.