Good question, incredibly difficult topic. We spent many hours debating this in the last months as we grew. Let me try to be very transparent about the outcome:
What? We will "not facilitate swaps involving any of these bitcoin addresses: https://github.com/0xB10C/ofac-sanctioned-digital-currency-addresses/blob/lists/sanctioned_addresses_XBT.txt", 376 as of today. Not more, but also not less.
Why (Short version)? : Because we can't become a tool that is used for serious crime. If we do, we won't make it. And we really want to make it.
Why (Long version)?: Many of our users use Boltz Swaps to increase privacy for very legit use cases, e.g. when depositing or withdrawing from KYCed services like CEXes or as precaution when e.g. moving to cold storage. We will be blocked by these services, the same way many of these services freeze your account if you deposit from addresses that were involved in a mixer/coinjoin. It would render Boltz useless for many of users, while it would help exactly none because we didn't have a single swap involving an OFAC listed address in the past. And anyways most addresses on this list are emptied or otherwise dormant. Also, as we are driving integrations of our API forward, some partners simply require us to be "OFAC compliant" otherwise they can't integrate. Because they are based in the U.S. or otherwise. So far the rational arguments.
I chose to do the risky thing and be blunt. Would love to hear your point of view!