Because China claims anything that has connections to China.  That's why they "own" the South China Sea and will claim the moon as soon as they get there.

Of course they do. To most people in the PRC, anyone with Chinese DNA is Chinese. I remember a while back, there was this big hoohah about an American porn star named Evelyn Lyn. She's Chinese American and netizens acted like it was a huge slap in the face that a girl of Chinese descent would be doing porn. It's pretty small minded and ignorant but that's just my opinion. 

Honestly, if it were possible, I think China would try to lay claim to every Chinatown across the world.

It's part of this collective mindset...  Yao Ming is good at basketball.  Yao Ming is Chinese.  Therefore, Chinese are good at basketball.

The same mindset seems to apply to anyone with Chinese heritage - but only if they do something wonderful or something really low.  If it's good, it's celebrated.  Bad, it's a disgrace.

Remember, individuality isn't as big of a deal here as it is in western cultures, so anyone remotely related to the collective is understood to simply "understand" these things.  This is of course not the case, but try explaining that to someone brought up in this culture.  This is one place where that "it's a different culture" argument really does apply.  There are 2 worlds:  that which is Chinese and that which is not.  There isn't much difference in most Chinese minds between America, Canada, Europe, Australia - it's "foreign", ie, not Chinese.  Being "Chinese" is so important to some people they can't fathom that anyone would not like it, lose touch with it, or simply abandon it in favor of something else.

you guys real talking right about chinese midset, chinese people have a strong "Big China" spirit since anicent .In this world we are biggest humen group who live this land for thousands years. we are insist thought this land are our home for ever.as a chinese whereever you go you still a "炎黄子孙"（descendands of Yellow Emperor ）.you should protect your homeland profits.
about ten years ago, chinese people can'ta accept  the truths that a chinese girl represent Japan beat chinese athlete in international sports. we call she is a"traitor" .
Now more and more chinese realize we are wrong, we shouldn't expect people protect china's profits because they was chinese or their parents were chinese. as a foreigner they should protect their country first. so when Gary Faye Locke become ambassador, we know we should treat him as a american not some kind of relative of chinese.

So does that mean Tiger Woods is Chinese because he has 1/4 in him?
The greatest Chinese golfer of all time!!!