Coinbase has been off and on. Think it was Saturday Coinbase (currently has a message they are caught up on backlog of trades), Binance (non since 1/5), and Bittrex (non since 12/15) all couldn't take new accounts. It's amazing to me how hard it is to get access to some coins due to this for new investors. Since so many alt coins are on limited exchanges and very limited exchanges for US customers having these 3 down at the same time makes getting started very hard.

Also shows the value of having accounts at multiple exchanges even if you don't really need them. If a coin comes along you want to trade and it's on limited exchanges and that exchange isn't taking new accounts you are out of luck. Or you may miss your window of opportunity due to the lag of being authenticated.