I would imagine there was probably at least one American aboard. Think things are tense with Russia now....look out.
I'm reading the Reddit thread now and they're assuming the same thing that Americans were probably on board as well as other NATO citizens. I think the world has stayed back because until now, it's just affected Ukraine.
http://www.reddit.com/r/worldnews/comments/2ayjwz/malaysian_plane_crashes_over_the_ukraine/