I downloaded some json files from Facebook and Instagram, most of them are about chatting records.
I found that every non-english characters is formed of something like this "\00HH". (ex: \u00e6\u00bb\u00b4\u00e5\u0085\u0092).
After some research, I figured out that this is just utf-8 code and decoded all of them, but I am still curious about why Facebook or Instagram didn't decode this for the users?? It seems that Facebook intends to do that??(but I can't find a reason)