I trust Bitstamp, but with all the Gox crap going on I can't help but wonder how much we are still in the Wild West with regards to legality and safety.
Two different views from the above thread:
1.
They are still mixing all client funds on a corporate account, without any kind of financial license whatsoever.
This will end bad, when UniCredit decides the party is over, then the party is over, Bitstamp gets sued in Slovenia, fined, pays the fine from customer deposits (which are legally their property since they sit on the corporate account), just like this happened to MtGox in France in 2011.
Kraken is in the same case, friendly bank, for now, but zero financial compliance despite all their marketing efforts to advertise the opposite.
2.
The strategy amongst banks seems to be to freeze out new BTC businesses and tell the potential customers some bullshit about "Bitcoin is so new, we can't comply with the regulations". Welcome to the world of banking soft regulation where there is absolutely nothing illegal about your business but you cannot get a bank account.