I think far too many people are being critical of @defcon for doing events outside of the US. The reality is, DEF CON is impossible to access for far too many people outside of the US because of US visa restrictions. This has always been a problem, but it has become a much bigger one lately.
For starters, the US has one of the world's most expensive visas. It now costs $424 per person (since the addition of the new "Visa Integrity Fee"). Additionally, the US requires in-person interviews to issue a visa, and these take place at a US embassy or consulate. Unless you live in your country's capital, you'll have travel expenses on top of it.
Then, of course, there are the delays for interviews. These can take months or even years. It was starting to get better, but the federal government laid off a large number of people who process visas, immediately resulting in extended delays. If you want to speak at DEF CON, and you're a foreigner, it's highly questionable whether you'll get a visa in time.
Finally, there is "extreme vetting" which is taking even more time. Suppose you're selected for "additional visa processing." What triggers this? The criteria are a secret, but there is a strong correlation with things like being a known hacker traveling to DEF CON.
Additionally, the US is denying visas for what they perceive as political speech (or expected political speech) that opposes the Party. This isn't unique in the world; other authoritarian countries like China also do this, which made it difficult for DEF CON to operate there.
DEF CON isn't unique in facing these challenges. The United States is closing the door to foreigners, limiting international collaboration, and limiting political speech. The only question is how to respond. Hosting DEF CON events in other locales, which guarantee research freedom and welcome international collaboration, is an entirely reasonable response. #defcon
