I know the term and have heard of the movie. I'm embarrassed to show my ignorance but could you explain the teory to me?
There used to be a website along these lines...you could sign up and make "connections", supposedly, with every single person on the Internet through these degrees.
Anyway, the theory is that everyone in the world is connected through six degrees or less...you know someone who knows other people who knows a bunch of other people, repeat six times, and eventually any complete stranger will be a "friend of a friend."
What this has to do with the current situation I'm not sure, except that someone we know must know someone who knows someone who knows someone who's been shot, etc. It doesn't matter. The fear comes from knowing it could happen anywhere, any time, not from knowing a victim.