Whatever one thinks about this or that particular symbol -- the use of political symbols on a site about mathematics is a distraction, and similarly off-topic as a question on mathematics on a press conference of the government.

So, let's have a look: you have 21 questions (not counting possible deleted ones) with median score 2, and of those questions 9 are closed and 3 have negative score. Unless I am mistaken, deleted questions count towards a question ban as well (though details are not publicly available). In order to get the software-side ban lifted, you might try to improve your deleted questions to get them undeleted (or undelete them yourself, in case you have deleted them yourself), and to improve your closed questions to get them reopened and upvoted. -- I hope this is of some help!

If you are trying to log in from China, maybe this problem is related to the Great Firewall?

I don't know how it comes that such question has 7 upvotes. -- Possibly there is some sock puppetry going on there.

Do you think that downvoting, closing, deleting and flagging are not sufficient to avoid such posts cluttering the site?

It seems that all the links are broken -- they are still to tea.mathoverflow.net, rather than mathoverflow.tqft.net. -- So without manually editing the URL's in the browser, one can see only the list of topics.

@YemonChoi: If one wants to make things right for every country which has less than one percent of the world's population, then one probably needs to stop doing anything at all ... .

Very nice answer. -- As I understand, originally the purpose of copyright law was to protect the rights of the authors and to allow them to financially benefit sufficiently from their works. I don't think the intention was to solely increase the revenue of publishers which get the copyright transferred from the authors for free, and to obstruct scientific progress by de facto hiding publications from a part of the community.

Indeed the Atiyah question on Meta was by far the most-viewed question on Meta at all -- see meta.mathoverflow.net/help/badges/28/famous-question .

Maybe part of the reason for closure is that the question has been asked anonymously, by a user-xyz.

As I read the description, you don't need 100 answers yourself -- upvoting $n$ competing answers to the same question counts $n$ times towards the 100. -- Or am I mistaken?

Good MO questions are specific questions, and not general ones about entire areas of research -- basically regardless of "how" the latter are asked.