Senator Rand Paul got a lot of chuckles—some admiring, some less so—for his bona fide talking filibuster Wednesday on the Senate floor, refusing to allow a vote on John Brennan's nomination to head the CIA unless he got a written guarantee from Attorney General Eric Holder that the government would not turn armed drones on Americans on U.S. soil. Paul's outrage was prompted by a letter from Holder suggesting, as Politico put it, that "in extreme circumstances, the executive branch might order lethal force against an American inside the U.S." To Paul, who co-sponsored a number of bills limiting the use of drones inside the U.S., this summoned images of Waziristan come to Wichita: "That Americans could be killed in a café in San Francisco or in a restaurant in Houston or at their home in Bowling Green, Kentucky, is an abomination. It is something that should not and cannot be tolerated in our country. I don't rise to oppose John Brennan's nomination simply for the person. I rise today for the principle."

Scoff all you want, but here's the thing: The prospect of the government or local law enforcement using armed drones to target people on American soil was discussed as a very real issue at a recent gathering of the drone lobby that I attended in Newport News, Virginia, the subject of a piece in the current issue of the magazine. The two-day gathering, organized by the Hampton Roads chapter of the Association for Unmanned Vehicle Systems International (aka the drone lobby), was focused on the vast opportunities and equally big challenges of the civilian market for drones—for crop monitoring, package delivery, police search and rescue efforts, you name it. There was much talk about the ethical quandaries and potential popular resistance associated with these uses. The conference organizers even brought in a theology professor to talk about the ethics of surveillance, complete with quotations from Foucault and Erich Fromm.

At several points, attendees veered toward the far touchier question of whether drones might ever be used over here the way they've been used over there: to kill bad guys, whether individual domestic terrorists or targets in a Branch Davidians–type situation. One speaker, Steven Bucci, a former Special Forces officer and Pentagon official now with the Heritage Foundation, rejected the notion outright, calling it "totally…a red line." "I don't think there's any place in a domestic context, short of an armed invasion, that we should be using armed drones in the United States, whether it's against U.S. citizens or anyone else," he said. "Domestically, I don't think you should ever see that…. We play by a different set of rules inside the territory of the United States." And a drone industry representative noted that police today do not arm the helicopters they use to track suspects, so why would they start arming the drones that they hope to use as a nimbler, less expensive tool for tracking and surveillance?

But a moment later, an executive with a major drone manufacturer pressed the point. If police are trying to take out a dangerous armed suspect but are unable to get a good angle on him, why would they not consider sending up a small armed drone, which, he said, is really just a gun put on a "remotely controlled platform." "I'm not necessarily so sure about the difference between putting a precision high-caliber rifle on a platform that you could gain a different perspective or access to some situation where it would be difficult to put a man in that spot…. If the bad guy's there and the only way you can deal with that is a remotely controlled platform I don't know why you would foreclose doing that." "That's an interesting issue," replied the theology professor, Daniel Bell Jr., of Lutheran Theological Southern Seminary. "UAVs have done such a wonderful job of taking out high value targets individually in a theater of combat—why not use that same kind of [tool to] take out high value targets domestically?"

It is indeed an interesting issue. On this one, Rand Paul may be on to something. Our drones have been tracking and killing people a long way away, and we don't particularly like thinking about that. But it will be past time for us to reckon with drones if they're tracking and even killing people closer to home.