So what!
What did he do?
How can you kill someone for running their mouth, unless they are on a battle field.
Justice was done. The verdict was correct and I would have been upset if it had gone the other way. There was little justification but the guy's own words to sentence him to death, and we don't do that sort of thing in this country.
It is only done in authoritarian regimes or dictatorships.
What really worries me is that people are reacting so emotionally to this verdict without any consideration given to the actual acts done. They could not even connect him directly with the conspiracy, as being the 20th high-jacker. If I used that same logic on other cases, I would have to kill all my relatives. (they have threatened me plenty)
What was actually done? Well, if I had driven one or more of my friends to a bank robbery, and one of them had killed someone in the process, I'd be as guilty as they, even though I'd never touched the gun. This guy was learning to make a passenger jet take off because he knew about a plan to attack our cities. He didn't need to learn to land because all he needed to know was how to hit a building.
Use your logic.