All you need to code Twitter is any language that can wrap SQL....

Add tweet: INSERT TABLE x (x) VALUES (@x, @userId)

Retrieve tweets: SELECT * FROM x WHERE UserId = @userId

I do respect some aspects of Scala, but using Twitter as a mark of success is worse than Hello World.

What is more likely:
1. China is conducting military hacking activities against allies in such a way that will attract negative attention.
2. China has a lot of easy-to-hack computers that more sophisticated non-Chinese hackers are using as relays for their own hacking.

Perhaps it is both, but I would bet that there is a whole lot of #2 going on.