[xyzzyz]

Ah, I meant to write that they routinely travel on _B1_ visa for work purposes -- I confused which one is tourist, and which one is business visa. And yes, the difference here is mostly immaterial, since most people simply get a dual B1/B2 visa.

> I wouldn't want to argue with USCIS about the letter of the law though, they'll deport first, ask questions later.

I don't think that's how it works in practice. It is quite rare that people are deported in cases like this, and much less on a short notice too.