The only exception would be if we are legally obligated to do so by a warrant or court order and even then only after speaking to legal counsel.
This is could become an expensive legal battle but you can likely pass on the costs to your customers because they will be willing to pay for the increased privacy you provide.
You should keep in mind that, according to this
law professor and former criminal defense attorney, there is
absolutely no reason to either communicate or cooperate with any law enforcement as anything you say can and will be used against you and even talking to them gives them an opportunity to commit perjury, which law enforcement officers do on a regular basis, that could have a detrimental effect on you.
So maintaining your right to silence, in the absence of a court order or warrant, is the only pragmatic path. The other pragmatic path would be to agree to talk if they offer you full and complete immunity (but make sure you have legal counsel to help craft the agreement).
Of course, you already know or should know the importance of making sure all your data is powerfully encrypted and secure with plausible deniability given the case
In re Boucher.
Currently, be sure you already have your legal defense(s) in place.
One thing that is so interesting about Bitcoin, and the legal battle that will come out of this, is the question: What is Bitcoin?
This is an important question because you are buying and selling whatever the heck this thing is. Consequently, it does not look so much like foreign currency exchange but perhaps more like paying for a PDF, ebook, piece of furniture or for personal services like a haircut?
For example, if you go buy a new couch or eBook from Amazon or hire an independent contractor for $2,000 then the merchant is not required to perform any KYC/AML, etc.
Then there is the issue about whether the person who buys or sells this nebulous and undefined thing is the same person that you transfer FRN$. This has to do with the GPU license on the Bitcoin source code, the lack of formal ownership over addresses and the plausible deniability that comes from anyone who has the private keys being able to 'control' a particular wallet.
Of course, none of this should be considered legal advice and I highly recommend you have competent legal counsel.