I you believe, as I do, that the general well-being of the governed is the primary rationale for the existence of government, and the source of its legitimacy, certain things follow.
Among them, in the current environment, is the need for some state security apparatus, a sort of early warning system for any sort of threat to that general well-being, combined with some means to effectively head off those threats or respond in the event they cannot be averted.
But in a world in which state security is a given, and a culture unto itself, one of the most poignant questions to be asked is in whose interest it acts. This breaks down into three more specific questions, relating to the law authorizing the existence and activities of such agencies, the political appointees who run them, and the career agents who rise through the ranks to exert a degree of control.
Of these three, the agents, faced with harsh, pragmatic realities, are the least likely to bend to changes in the political wind, while the political appointees running the agencies are the most. Law moves more slowly, but it too grows in reflection of the prevailing winds of the times. That's not to say that the agents are necessarily more interested in the general well-being of the governed than their bosses, but that can be one result.
This might make the agents seem hard-nosed and unresponsive, but they have a job to do. What's more material is how they conceive of that job, and how they are directed by law and agency administrators, whether it is truly in service of the general well-being or whether it is in service of something else, something more in line with the agenda of the Koch brothers.
Efforts to 'out' agents, like the recent mining of LinkedIn data, are sure to expose many well-intentioned people for every bad actor they uncover, and paint them all with the same brush. While it does possess a certain ironic quality, the net effect will be to thicken the wall between the agents and the general populace they serve. This is not useful.