This user seems to be using a bot to spam introduceyourself posts and then goes and self-upvotes those spams about 4-6 days later with 150+ accounts that are using delegated steem from steemit.com.
I'm sure this is not the only person who's doing something like this. But if we do not stop these [ab]users, things will only get worse! This user has been warned but has not stopped abusing the system. I encourage anyone who has some spare power to flag the comments that have not got paid yet.
https://steemit.com/introduceyourself/@yuxin/am-i-part-of-the-150-000-steemit-users-already#@god-is-love/re-yuxin-am-i-part-of-the-150-000-steemit-users-already-20170822t080537640z