Possible crime type - Bitcoin promoting to China people. What do you think ?
China can say that Bitcointalk China subforums, which promote Bitcoin are not legal in their country and therefore have wide impact on China in unlegal way, which can be the crime according to Chinese criminal law.
China as the state can ask to transfer persons from other countries in criminal cases, it depends from international agreements and local Chinese criminal law. USA for example, do not have direct extradition agreement with China, but can extradite case by case.
In some cases based on residence country law, persons are not transfered, but that's exception. Each year there are hundreds of such cases between countries in the world.
China is also Marxist–Leninist one-party socialist republic, so different political system, see here -
https://en.wikipedia.org/wiki/China.
What Is Extradition? Which countries have extradition treaties with the United States? -
https://www.cfr.org/backgrounder/what-extraditionhaving a Chinese local board on a forum does not mean the forum promotes Bitcoin to the Chinese people. they can claim that the forum "promotes" Bitcoin to the Chinese people all they want but that doesn't mean it is true nor does the country where the forum is based would go along with what China wants.
anyway, I am really curious as I have said before in my previous post on this thread, I've seen you targeting the admins in the threads you have created before, would you mind answering this, what is it exactly that you want from them?