An ad hominem attack is where, instead of refuting a person's arguments, you attack their character. It's a fallacy that enlightened people avoid. I point this out because of a The Intercept piece about how some of NSA's defenders have financial ties to the NSA. This is a fallacy.
The first rule of NSA club is don't talk about NSA club. The intelligence community frequently publishes rules to this effect to all their employees, contractors, and anybody else under their thumb. They don't want their people talking about the NSA, even in defense. Their preferred defense is lobbying politicians privately in back rooms. They hate having things out in the public. Or, when they do want something public, they want to control the messaging (they are control freaks). They don't want their supporters muddying the waters with conflicting messaging, even if it is all positive. What they fear most is bad supporters, the type that does more harm than good. Inevitably, some defender of the NSA is going to say "ragheads must die", and that'll be the one thing attackers will cherry pick to smear the NSA's reputation.
Thus, you can tell how close somebody is to the NSA by how much they talk about the NSA -- the closer to the NSA they are, the less they talk about it. That's how you know that I'm mostly an outsider -- if I actually had the close ties to the NSA that some people think I do, then I couldn't publish this blogpost.
Note that there are a few cases where this might not apply, like Michael Hayden (former head) and Stewart Baker (former chief lawyer). Presumably, these guys have such close ties with insiders that they can coordinate messaging. But they are exceptions, not the rule.
The idea of "conflict of interest" is a fallacy because it works both ways. You'd expect employees of the NSA to like the NSA. But at the same time, you'd expect that those who like the NSA would also seek a job at the NSA. Thus, it's likely they sincerely like the NSA, and not just because they are paid to do so.
This applies even to Edward Snowden himself. In an interview, he said of the NSA "These are good people trying to do hard work for good reasons". He went to work for the intelligence community because he believe in their mission, that they were good people. He leaked the information because he felt the NSA overstepped their bounds, not because the mission of spying for your country was wrong.
If the "conflict of interest" fallacy were correct, then it would apply to The Intercept as well, whose entire purpose is to fan the flames of outrage over the NSA. If the conflict of interest about NSA contractors is a matter of public concern, then so is the amount Glenn Greenwald is getting paid for his stash of Snowden secrets, and how much Snowden gets paid living in Russia.
The reality is this. Those who attack the NSA, like The Intercept, are probably sincere in their attacks. Likewise, those who defend the NSA are likely sincere in their defense.
As the book Too Kill a Mockingbird said, you don't truly know somebody until you've walked a mile in their shoes. Many defend the NSA simply because they've walked a mile in the NSA's shoes. I say this from my own personal perspective. True, I often attack the NSA, because I agree with Snowden that surveillance has gone too far. But at the same time, again like Snowden, I feel they've been unfairly demonized -- because I've seen them up close and personal. In the intelligence community, it's the NSA who takes civil rights seriously, and it's organizations like the DEA, ATF, and FBI that'll readily stomp on your rights. We should be hating these other organizations more than the NSA.
It's those like The Intercept who are the questionable bigots here. They make no attempt to see things from another point of view. As a technical expert, I know their stories based on Snowden leaks are often bunk -- exploited to trigger rage with little interest in understanding the truth.
Stewart Baker and Michael Hayden are fascist pieces of crap who want a police state. That doesn't mean their arguments are always invalid, though. They know a lot about the NSA. They are worth considering, even if wrong.