I am trying to find the title of a science fiction short story I read back in the 1970s. The story takes place in a congressional hearing, in which a rancher details how while trying to invent/build an improved cattle fence he inadvertently created an extremely powerful laser. He shows the plans for the device, which automatically puts them into public record and distributes them, so that anyone can easily recreate the powerful weapon he has discovered. A Congressman tries to stop the meeting, but can not do so before the plans are broadcast. The rancher admits he did this on purpose because he doesn't think the government should have sole access to this technology. Does anyone know this story?