The majority of these employees (the vast majority) have nothing to do with the NSA or related activities. Even tangentially. Those being furloughed seem to be in the industrial/manufacturing sectors. These are people making the aircraft, ground vehicles or components for them. Future furloughs will hit those whose contracts were to get funding this fiscal year (appropriations can span multiple years, so it's possible a contract is funded despite this, but many may not be funded until after this current budget is passed). And companies will likely use this as an excuse to save some money by furloughing more employees than just the ones on affected projects. And in turn I wouldn't be surprised if they try to change the terms of their existing contracts to stretch out deadlines, even contracts that shouldn't have been effected. Hooray! More money down the drain.
I'm tempted to resort to hyperbole of my own, but suffice to say that if you work for a defense contractor, the fact that your job doesn't directly contribute to people being exploded does not absolve you.
Supporting the armed forces when we face a realistic and imminent threat, from an enemy we can actually name, is a fine thing. We are not in that situation by any stretch.