Black bars are essentially free; I never got the reason to ration them. While Glenn may not have been a part of the hacker community, he's an international icon of science, technology, and space exploration. I would guess a nontrivial number of people here have been positively influenced by John Glenn, and I'm sure every single person here has at least heard of him. I believe a black bar would be appropriate, as this is the only opportunity that we have to honor his passing.
