(Free Tibet) Why Tibet??

I hope without sounding insensitive, and with a real sincerity, I
ask...Why is the political issues of Tibet so important? It's an issue
I see on Bumper Stickers and Tee-Shirts all the time, and I've seen it
for the better part of a decade. But what I don't understand is where
does the passion come from? Why Tibet? Why not (insert favorite
African nation here) or any half dozen (extreme)Islamic nations under
oppression (as oppossed to the Moderates in the region)? How about
Free N. Korea or Cuba? I guess everyone picks their battles, but Tibet
just doen't seem to be the worse place...all other things being equal.
But again, I realise in asking I am in a position of ignorance on the
Tibet matter. That's why I'm here...for you to explain it to me.