Legally a Chinese citizen can only move up to $50k USD out of China per year (and they have to report those expenses) [1]. There are various techniques wealthy Chinese use to get around this but BTC had the ability to be the one of the easiest and least-traceable. Not everything traces back to BTC but it is a telling sign of a larger trend.
1. https://www.inman.com/2017/01/03/new-rule-china-may-affect-o...