In their defence, don't shoot the messenger. Just because they published it doesn't mean that others haven't already discovered it. Better to know its possible than be completely ignorant.
Then maybe publish the results, but don't publish the "how to".
> Just because they published it doesn't mean that others haven't already discovered it.
That’s irrelevant for the moral evaluation. Everyone is responsible for their own actions. If you choose not to kill anyone it won’t stop others from killing. But the fact that this is so doesn’t give you a license to kill.