The purpose of this is it is unlikely illegal immigrants will register with the government.
They now have a criminal violation, which gives them a basis to use IRS databases to locate illegal immigrants.

These restrictions apply to people who arrive on nonimmigrant visas. You also have to notify the government of any change of address.

Anonymous wrote:

This has been the law since 1940. Trump is the only one to enforce it since the 50s or 60s though.

Source?
Because if it was already the law, why would he need an EO?

They had to set up the registration system.
The law is cited in the original post.

Anonymous wrote:

Anonymous wrote: That's not a valid comparison. Neither is keeping a passport with you if you are visiting another country; it isn't legally required and you can't be picked up off the street at any time without it.

Ever been to China? Yes, you do have to keep your passport with you wherever you go, you also have to give it to every hotel you go to, they have to call it in to the communist party they track you. You have to give them your travel itinerary, before you go.

Good to know we are Making America Communist Again.