[rshlo]

This is very strange. In Israel all citizens are required to issue a tourist visa before traveling to the US. The process is super quick. The embassy have a website that updates you on each step in the process and from applying until you get the actual visa it can take only 3 weeks. The only busy times are usually in summer months where many tourists want to issue visas, so waiting for the in person interview can be up to a month. But again, from the interview to getting the actual the visa is a matter of days.

[Scoundreller]

He’s swedish, so he enters under the Western Hemisphere Travel Initiative which doesn’t require a visa, but usually requires an ESTA.

An ESTA is not a visa (otherwise the US could lose its reciprocal visa-free travel arrangements). The ESTA just walks, talks and quacks like a visa.

[Macha]

Note that their is a distinction. While arguably even the ESTA is too much paperwork compared to what US citizens going the other way under these visa-free agreements face, it's a short form you fill out online that gets automatically approved within 12 hours for 95% of cases. It's when you get denied for this system (and yes, this can be for arbitrary reasons which they won't disclose), that things go wrong. It would not surprise me if the logic went "owns domain haxx + curl is used in hacker tools (and many many more legitimate uses, but some agent doesn't care)", "possible hacker", "put on list that causes ESTA denials".