From the Asahi Shinbun:

In Japan Social media present workplace intrusion into private life

When I left Japan 3 years ago, facebook was slow to catch on in Japan.  Another social media website, mixi (W), was much more popular among Japanese people, supposedly because it's closed networks (which you needed an invitation to join) was much more suited to Japanese culture. But I think by now Japan is just as linked into facebook as everywhere else.
(Correct me if I'm wrong, friends in Japan.)

It's funny how something that is relatively benign in on one culture creates such headaches in another culture just due to all these little cultural differences.
My favorite part of this article was the bosses who demanded that they get more comments on their facebook postings.  And I also liked the employee who now considers it part of his workday duties to read his bosses facebook page and "like" everything his boss says.