Sort:  

That account is the central account for all deposits and withdrawals of STEEM and SBD into their exchange. Instead of having individual STEEM/SBD wallets, the exchange creates their own version of accounting and internal wallet. The memo attached to the transfer allows the exchange keep track of who has what. When they disabled the wallets, that STEEM and SBD on the Poloniex account is the result of many people's deposits into the exchange.

Well stated!

And what is your goal for Steemit?

Btw thanks for following me. I hope you will be able to read my posts together with those from the other 20k accounts you follow. I mean how will you do that?

Coin Marketplace

STEEM 0.19
TRX 0.24
JST 0.037
BTC 96612.01
ETH 3387.37
USDT 1.00
SBD 3.05