Sort:  

They were the easiest (among Coinbase, Bittrex, Poloniex, Gemini, or Kraken) to create an account in since you could start trading without validation. They could easily have people with multiple accounts and fake accounts trading.

exactly this is what happened server system is collapsed due to too much traffic

Coin Marketplace

STEEM 0.08
TRX 0.29
JST 0.036
BTC 101693.82
ETH 3376.39
USDT 1.00
SBD 0.57