Scientist have moral responsibility not to build weapons of mass destruction for example. Too bad even Einstein couldn't keep with your advice. Scientists are sometimes not so smart. They can be fooled like anybody else.
"Hey you're inventing a machine gun!" "No I'm not, and even if I was, machine guns can be used for many things other than violence!"
Edit: Also, Einstein in this analogy is the one cautioning about someone being able to invent a machine gun.