There are hundreds of similar complaints about Coinbase on their sub-reddit just within the last week or so, many including support ticket numbers. People are getting pretty freaked.
https://www.reddit.com/r/coinbase
FYI this is identical to what happened on Mt Gox. It was easy to send money in, but getting more than 0.5 BTC out became quite difficult.
That said, it seems closer to the truth to say that they're simply under load. But it's hard not to wonder. There's no way to know there's a problem until it's too late.
It's a good reminder to keep your coins off Coinbase.
> It's a good reminder to keep your coins off Coinbase.
I'm finding that keeping coins off of Coinbase is easier to do than keeping cash off of Coinbase. It's fast and cheap to transfer cryptocoins to Coinbase, but takes me days to add cash.