Similar story with Sony patenting brain interface[1] . Funny thing was after watching the Matrix the first time, me and a friend were debating why people would want to insert something directly into the skull and mess around with neurons possibly. I suggested using sound waves to trigger nerve signals, he laughed at silly idea and it was forgotten . A year later saw the Sony patent on slashdot and for a few minutes i really did think they had done some work on this, till i realized they had just called 'Dibs' on the idea.

[1] http://www.newscientist.com/article/mg18624944.600-sony-pate...

At that time Feynman was filing patents on behalf of the government during wartime when there were other concerns than wildly trying to grasp any possible market. I would guess that the government was trying to ensure that individuals and corporations would not be in a position to obtain a monopoly on an invention that could gain the US a tactical/strategic advantage in the war.

Ah, the good old days, when the government would simply abuse the existing legal process to screw the little guy instead of just declaring a new process by fiat ala NSL/executive order/etc when it suits them.