5.4.2.1. Is Stack Overflow blocked in China? (Stack Overflow 在中国被封锁了吗？)
There was no clear evidence of that as of April 2020: https://meta.stackoverflow.com/questions/267715/is-stack-overflow-accessible-in-china/288497#288497
It worth noting however that as mentioned at Is Stack Overflow blocked in China? (Stack Overflow 在中国被封锁了吗？) that websites can become non-functional if CDNs they rely on are taken down, instead of the website being taken down itself.
For example, Stack Overflow relied on Google for some of its JavaScript and on Imgur for images, both of which are blocked in China.
There was no clear evidence of that as of April 2020: https://meta.stackoverflow.com/questions/267715/is-stack-overflow-accessible-in-china/288497#288497
It worth noting however that as mentioned at Is Stack Overflow blocked in China? (Stack Overflow 在中国被封锁了吗？) that websites can become non-functional if CDNs they rely on are taken down, instead of the website being taken down itself.
For example, Stack Overflow relied on Google for some of its JavaScript and on Imgur for images, both of which are blocked in China.