[zhuzhuor]

AFAIK, USA has been a second choice for crypto-related conferences for many years. If you ever attended one such conference, you will notice there will always some speakers/presenters couldn't attend due to visa issues. I guess many US people aren't even aware of this, but visa problem has been a huge pain for non US citizens. You can ask about this if you have any friends who are international students or H1B workers.