regarding @virgilgr. The legislation being invoked is the "North Korea Sanctions and Policy Enhancement Act of 2016".

The claim is that there is a 'provision of service' to dprk. The other arguments are a bit of a drag net - not all of them are clear violations.

Travel is a point that the legislation claims needs approval, but the validity of the legislation on this point has been questioned. In particular during the travel ban to Cuba in the 1960s. Arguments have been made that the constitution protects freedom of movement.

Arguing that a single conference talk on blockchain technology constitutes meaningful tech transfer will be a tough claim - it’s difficult to disprove that knowledge was not already known, especially in the likely event that the contents are generally available online.

The main thing that’s going to likely end up at the crux on the prosecution side is the details of the proposed financial transfers, if the occurred, and what role was played there.

Worth also noting that this is the first invocation of this legislation that I’m aware of.

The other context to provide is on the 'conference'. One effect of the 2016 sanctions has been to discourage travel agencies from taking US citizens. Most english-speaking agencies are based in China, us the US banking system, and don't want that risk.

The Korean Friendship Association (KFA) is the exception - it doesn't have as much external prsence, and would like be tougher to fine / sanction. My impression of the conference agenda was that it was essentially a package tourism trip.

here's more context: https://www.nknews.org/2019/09/friendship-group-to-host-pyongyang-blockchain-cryptocurrency-conference-in-2020/ In particular, the trip was co-organized by one Chris Emms, who has quite the linkedin background, and no apparent connection to the DPRK. https://www.linkedin.com/in/christopher-emms/