Indeed, it is very frightening what the companies can do with user's data. While in U.S, the data of a user may reside in the cloud of multiple companies and needs to be aggregated to be useful, in China, companies like Tencent knows about almost everything about every user: your IM messages, your purchases, the movies/music you like, the news you read, your geolocation. I cannot imagine what they are capable of with all those data. Think black mirror.