It happened on UA896 HKG-ORD on Feb 15 Wed..

A violent passenger slightly injured the shoulder of a male FA.
UA896 was diverted, landed at NRT at around 16:30 and left there around 18:00.
The suspect is being detained at NRT.

At this moment Google finds no English article on this.

While in Japanese,
Video:
http://news.tbs.co.jp/newseye/tbs_newseye4953721.html
http://www.fnn-news.com/news/headlin...N00217354.html
Kanji and kana:
http://www.tokyo-np.co.jp/s/article/...501001838.html
http://www.yomiuri.co.jp/national/ne...OYT1T01048.htm

Looks like no one has posted about this. So does that mean, in this kind of situation, passengers are not allowed to use the phones?
I hope the man in a yellow T-Shirt is not a FTer.
The Yomiuri article above tells that Japanese police don't have the right to arrest him since the crime was not committed in Japanese territory. So I am wondering what supports the detention.