[Ramius]

Actually, all of the hijackers were here legally, at least at first, on student visas. Some of the visas had expired but they originally had legally entered.

[muawiyah]

Another term to use "out of status" or "change of status". You can enter the US legally, have a visa that's still "valid" as far as the expiration date is concerned, and yet, due to "change of status" you can be "out of status" and need to go home, or elsewhere, to obtain a new visa.

For example, you might be here on a student visa, school ends, and you decide to burn up the rest of your time cruising the highways.

That's a "change of status", from student to tourist, and you become "out of status".

Time to go home.

Technically ICE could bust you for it. In reality, they don't bother unless you commit another crime. Then you get the free dormitory treatment and are sent home.