Bing is accessible from China. FB and Twitter must comply with censorship rules and storage of user data in China, among other things, to operate in China. Google was operating and accessible in China until China made clear the rules for them to follow. Google decided it couldn't follow they they pulled out the search engine business from China. China didn't force Google to sell. Censorship is bad but that is another issue.

And to do personal attack doesn't make you look smart.

Yeah, I think that was their mistake. Though I personally commend Google for standing up for their ideals at that time as to how they thought about information and access to it.

But it is not like PRC makes it easy to do business there. There is a well known episode of a breach orchestrated by PLA. https://en.m.wikipedia.org/wiki/Operation_Aurora

So what? If CCP isn't allowed to be defended here, isn't this place exactly what CCP is?

He has such an account because he wants to remain anonymous because views such as his are such that people like you would censor and ostracize him. Such is the hypocrisy of one who cries for freedom and free speech.

That rule seems a little strange. What if it happens to be, legitimately, only a single purpose that interests you? For example if you only commented about your favorite framework...