Well, polo. But it would seem that anyone who has "Routine Server Maintenance" during a brutal downswing in the market is probably cheating somehow too.
That would mean Bittrex too for a time.

Strange that everything just keeps ticking along fine on this end but those guys cant keep their steem wallets running.

But what I really want to know is why these guys all have so much steem parked in their steemit wallets. I realize that I am pretty dense, so I don't expect all the details, but for Polo to have 21 million steem sitting here is a mystery to me. I thought they took possession of all the coins that they exchange? It would seem to me that their entire steem market on their end could be paper, until such time as someone wants to actually transfer it somewhere.
And at that time, their wallet is broken.

I think it is BS and a ponzi scheme. They love the liquidity that steem gives them, until someone actually wants to sell into a market collapse.