How many people do you think crime syndicates employ? Also, maybe coinbase has changed its policies but when I signed up I just needed a bank account #. Also, if you don't intend to transfer to/from fiat, Coinbase doesn't need any ID AFAICT. So you transfer your several thousand bitcoin from your private wallet into the coinbase accounts you control. You then use coinbase's free exchange to send those coins to your laundered wallet that is set up for a legitimate cut-out business with all the right paperwork & whatnot for converting it to USD.

You do this so that each individual account can make small purchases over a long time horizon so it looks valid. Looking at coinbase's site, you only need a bank account if you're using fiat currencies. You'd probably also want to make it harder to detect all your laundering accounts by having them make purchases to other "legitimate" accounts too (e.g overstock) Obviously I'm not a criminal mastermind so this plan could very well fail, but I find it hard to believe that a digital cash currency couldn't be used to effectively launder money considering laundering is most effective for all-cash businesses (combined with good accountants/bankers like illegal organization employ these days to avoid all these problems).