@themarkymark
Do not only contact Binance (he could have traded here anonymously). There are also transactions that lead from Bittrex to @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: @zombee (and even @magicdice1) has indeed made a few transactions to @bittrex - and with one memo for each coin (SBD/STEEM).