Dude, the only privacy they care about is their own.  According to my Chinese friends, being with only your underwear inside of your apartment with the windows open, no drapes drawn, is common and normal, because one you can not really see a thing, and two, no Chinese man or woman will look into another apartment.

You should consider moving to my building complex, in mine you will see many women (more than men), in PJ's, underwear or just naked walking around inside their apartments. And of course, in PJ's or underwear in hallways.

I don't really think it is whether or not they care about privacy, it is more like not being aware that such a thing exists in the first place.

An American female friend of mine was unlucky enough to have her apartment next to a building site. She insisted on curtains as she was subjected to harassment on entering and leaving the building. She asked her school to move her, but they wouldn't. I'd like to think i was secure in my own place, particularly if I was the only foreigner in the block, as i was in my last school. So curtains are a must !!

privacy,,,  hehe,, that cracks me up....    watch them sometime...  funniest (odd) thing I ever saw (seen?) was those open area restrooms. u know, the ones that are just a big room of squat toilets with no partition walls. One guy taking a dump (I hate to talk like that,, but it describes it perfectly) while smoking a cig and his friend standing there beside him while they chat (loudly) about whatever it is they chat about.  I Have seen this. Not by choice, believe me.

I remember one guy describe Chinas perfectly,, he said  ' they like being loud, and they like being together.'  say's it all I think.....

In the village you could walk around in your jamjams without anyone seeing, as everyone lives on the ground floor. Now that the village has been stacked it takes time to adjust. 

I find the opposite. In my old building it no one had the curtains open. 

I often see fat men walking around in their undies.  At first I thought "oh my god", then I thought "oh that's beautiful" - sarcasm by the way...  But now I compete with them!

get some obstackles and do it obviously, either way they will call the police or they will close their curtain or they like it

Flip side is they sure know your business.

People here certainly have a different attitude to privacy but it's not necessarily something to scorn about. You are a guest in this country and should accept that people's attitudes are different here. I for one, am not offended by people walking around in underwear and think it's great that people are not so uptight and prudish. I see far worse things on the news every day which are truly worth complaining about like the atrocities in Syria for example.  Just get over it and enjoy your time here. There's plenty of beauty to admire if you choose to open your eyes to it.

Some do some don't. Maybe they just couldn't tell or didn't know that you could see them through their windows...

Privacy means many things to many people. We are guests in china, their standards are different from ours. So be prepared for anything. 

I am always surprised that they seem to think having the door wide open so everyone can see their dongxi.  Where they all born in a barn?