Hive account@themarkymark
Do not only contact Binance (he could have traded here anonymously). There are also transactions that lead from Bittrex to Hive account@magicdice (6 months ago). I am really convinced that withdrawals from Bittrex were stopped for unverified users. Even in late 2017, the limit was lowered to 0.025 BTC, but this transaction contains 5k SBD. I hope this could help a lot with identifying him.

EDIT: Hive account@zombee (and even Hive account@magicdice1) has indeed made a few transactions to Hive account@bittrex - and with one memo for each coin (SBD/STEEM).