Is there anything anyone can do that justifies violence or threats of violence? No. Even if that person is a proven child molestater, a just society stands on just law.

But as far as political justification stands, he is as valid of a target for hostile nations just as Iranian nuclear scientists were (unless he has 0 involvment with USG). That's just the world we live in.

Use your tech for war in other nations, you give a justification for other nations to target you. Same goes for Lockheed Martin ceo etc, nothing specific against Sam. But saying nobody has no valid reason to target Sam like this is pretty stupid imo.