what makes a story go national, or international?
Certain incidents and events become known across a nation where many or most people are aware of them, thinking, talking and feeling about them. Here in the U.S. I can think recently of the trial of George Zimmerman who killed Trayvon Martin as one such story, and Miley Cyrus's appearance at the VMA awards where she "twerked" vigorously as another. One international story is the problems of Greece, and I imagine Barack Obama's election made some waves in other countries (did it?) What is it that makes certain stories get many people's attention and awareness? Is it that there's a lot of emotion in the events involved? Is it that something in the story impinges on many other people's lives, and how does that work? Perhaps there are different factors for why different stories become prominent?
For those in other than the U.S., what stories have gone national in your country?