Ethical Riot Control?

Hilzoy at Obsidian Wings posts on this New Scientist article concerning new research into the laser-induced infliction of great pain at a distance of up to two kilometers as a possible means of riot control.

The article sums up the proposed device as follows:

[S]o-called Pulsed Energy Projectiles (PEPs), which fire a laser pulse that generates a burst of expanding plasma when it hits something solid, like a person (New Scientist print edition, 12 October 2002). The weapon, destined for use in 2007, could literally knock rioters off their feet.

Perhaps it is needless to say that various individuals and groups have expressed grave reservations about this technology, both with regard to its intended use (focusing on the potential for permanent neurological damage) and its possible misuse (most obviously, as an interrogation tactic). One critic, in fact, is so strident that he foolishly suggests that the mere possibility that a technology is fit for misuse justifies censuring the researchers behind it:

John Wood of University College London, UK, an expert in how the brain perceives pain, says the researchers involved in the project should face censure. "It could be used for torture," he says, "the [researchers] must be aware of this."

This reasoning, in isolation, is utterly unsound. First, toenail clippers can be used for torture. Plenty of technologically primitive means of torture have been deployed at Abu-Ghraib and Guantanamo. Second, every other means of riot control (any item used hand to hand, shotguns firing misnamed "non-lethal" projectiles, tasers) has the potential not just to permanently harm its targets but also to maim or kill them. Hilzoy writes,

surely, I thought, while evil cackling mad scientists or manufacturers targeting the sadist market might aim to cause pain per se, my government would not.

But apparently I was wrong.

What is happening to us?

I'm a leftie, I bleed for rioters, bla bla bla. Moreover, that maximization of pain is the researchers' explicit goal troubles me. But if pain is the source of the immobilization sought, than maximizing it is consonant with the underlying goal. The soundness or ethical status of the means must be considered in this light.

If someone comes up with a way to subdue people who justifiably should be subdued that doesn't entail a lethal risk, I'm all for it. If the means to that end is the infliction of merciless pain, so be it. For my money, the choice between enduring tremendous but transient pain or taking a wax bullet in the eye is no choice at all. As for the potential for misuse, this is almost always a red herring, a rhetorical device on par with attenuated slippery slope arguments: manolo blahniks can be misused to dangerous effect as well, but they still look good.