and meanwhile the price is dropping fast and hard.
this is not exactly the best practice but for all the altcoins, specially those known to have serious problems such as ethereum, it is best to always keep them on exchanges to dump them fast and always cash out the BTC or USD to cold storage.
to all you who have your deposits stuck and are losing money, you have my sympathy.
edit: i can see other exchanges have done the same. Coinbase is saying "investigating..." (https://status.coinbase.com/) and i have heard that poloniex has also been experiencing issues.
Ethereum blockchain is collapsing due too many ICOs generating too much activity, it is becoming bloated all the time because millions worth of ETH transactions are transacted all the time due the never ending ICOs.
It is never a good idea to have your money sitting on an exchange anyway, this is another reminder.