Those affected weren't from the third world though. I have travelled for conferences in the US several times, now I'd be worried they'd argue you need a B-1 vi

Those affected weren't from the third world though. I have travelled for conferences in the US several times, now I'd be worried they'd argue you need a B-1 visa instead of ESTA waiver if you visit the company office after the conference, etc. And detain you for weeks when you don't have it. The USA is supposed to be the land of the free.