Quote Originally Posted by jd421 View Post
When you visit the UK, they collect your passport at the hotel. You could confirm their reservations or who they will be visiting.
When they leave the hotel where they are staying they can get in a cab and go anywhere, airport, bus station, etc. and head for parts unknown. They don't need their old passport, they aren't going back home. Their new fake ID let's them be who ever they want to be.


You can collect their credit card numbers. You can stop them from buying car tags and getting driver's licenses.
All they have to do is stop using their credit card from back home and you have lost the ability to track them.
Illegal aliens already can't get a license in most states. That's why they get a fake ID and become someone else.

You can arrest the home owner who they were to visit. You can alert authorities if they cancel or rebook their flight home.
If they are here on a tourist visa, staying in a hotel, and say they are going to Disneyland who do you arrest when they disappear?
If they are here on a student visa and disappear from the school who gets arrested?
If they cancel their flight home you have no idea where in the country they are, so where do you look for them?

Thats about it I suppose. I don't know what you could take or withhold from them to make sure they leave. Maybe if their family was arrested in their home country, they would leave.
I don't think you can arrest people back home for something a family member does in another country. Would it be legal for the police to arrest you for something one of your relatives did.

This goes for "Guest Workers" too. Once you let them in you loose control of them.
They can cross the border and say they are headed to work on a farm in New York and get on a bus for there. Get off at any stop and go where ever they want.