I dunno if you guise know, but Mt.Gox started doing exactly the same thing months ago. So I don't understand why is so many people so surprised by this...
I think they are freaking because MtGox only requires when you trigger their suspicious activity while Bitcoinica will require verification for all users to trade.
Mt. Gox will request identification information (such as an identity card, invoices, Government issued photographic identification, utility bill, residential certificate, signed certification of cohabitation, or similar, banking information) depending on the amounts deposited on the Accounts or the presence of suspicious activity which may indicate money-laundering or other illegal activity.
Under American law, it is a crime to notify the customer that they filled out a Suspicious Activity Report
on them. At least it is possible to know a MtGox customer potentially had a SAR filed.
I am hoping that that someone sets up an unaffiliated Tor hidden services that allows users to buy and sell bitcoins but connects into the large networks to take advantage of the volume.