No Harsh Criticism! Sometimes I think it seems that some kinds of threads(What do you think of Chinese food?  What do you think of Russia? Something like that)might intend only positive replies from people. However,  Inevitably it can cause replies that look even a bit ignorant, because we can't know everything about reality of each country, and our knowleage is quite limitted. Or it might get some feedbacks of unpleasant prejudice, also because people from other countries might not know true things about the country. We need to allow people to express their opinions.(but just carefully and more politely because it is connected subtle cultural, social, and political issues) And if some replies are not true or biased unintentionally, other people can correct in friendly manner. No harsh criticism for just criticism.