Endorsed is unlikely. Tolerated moreso than other protests might be.* There's lots of riot police around the Japanese embassy from what I hear, but no real effort to break the thing up.
* imagine the backlash if this particular protest was actually put down. So they won't.
The Chinese are pitching high and inside to let Japan know they're serious about territorial issues.
I doubt that is the case. This results in nothing but destruction of economic value - most of the small shops being overrun are owned by Chinese anyways, all the property damage is in China etc. I also presume that the workers at the Honda/Panasonic/etc. plants are not being paid. It would be like showing someone you're serious by punching yourself.
More likely a "tipping point" type moment that just grew out of grassroots anger at "everything". Tomorrow (today, in Asia time) is the anniversary of the Japanese invasion of northern China so that combined with the islands purchase (this isn't really about the islands, that's just a catalyst), plus economic growth that is much slower than what people are used to, in a country that still has lots of deep seated social problems and economic injustice, and sometimes things are going to get out of hand. Mobs tend to do that.
Not justifying it - its actually extremely irrational as most mobs are. Just my two cents on the
underlying causes.
Similarly, are the Middle East protests really about that one video? Or is there something deeper and that video is just another spark for the fire?