Exactly. There are two categories of visa waiver - WT (tourist) and WB (business). You get the same stamp which has both written on them, if they remember they circle the one that applies to you.

I have heard of other cases like this one (including the son of people I know) where people arrived in the USA in good faith thinking that they were going to be covered by the visa waiver scheme and finding that they were not. Their stories are the same - they were all treated like criminals. Yes, they should have known better, but clearly there was no criminal intent - they had merely misread the rules and made a mistake. Send them back by all means - after all, they are not entitled to enter the country. But treat them like criminals? Handcuff them? Why? They have not stolen anything, they have not murdered anyone, they have not hurt anyone, they have not defrauded anyone. They were acting in good faith, intending to enter the USA for a temporaray visit for entirely legitimate purposes.

By contrast with these stories we read from the USA... :

I know two people who tried to enter the UK without the correct paperwork. One was an Australian who, like the journalist in our story, had been too honest - "I've come to join my British wife" rather than "I've come as a tourist". As he was joining his wife he needed a residence permit which he should have sorted out before leaving Australia.

The other person actually had a work permit, but did not realise that because her work permit related to a teaching job it did not entitle her to re-enter the country after the end of July even though it was valid until the end of August.

Both these people were treated with respect and courtesy and had their mistakes explained to them calmly and politely. The teacher was eventually admitted, the Australian was put on the next flight home - NOT in handcuffs, but as a free person. He was simply given a boarding card and was sent on his way and was free to wander round Heathrow while waiting for his flight to depart.