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The researchers working with the sharks probably want their ideas to actually be used for war about as much as I do (which is to say, not at all). They also know that the likelyhood of this actually happening is quite small.
I would bet that the researchers working on this project are much more interested in solving deep questions on how the brain and body work together.
As a phd student in a large research university, I know many researchers funded by DARPA or organizations with military leanings. These researchers would prefer not to get money from these places, but in some sense, as long as they can spin their research in terms of benefit to the military, there are no strings attached. That's a good thing for science. This is exactly how the internet was created.