The security chief was supposed to prevent dangerous aliens from attacking the ship's crew.

California prevented aliens (mainly Asians) from holding title to land until the law was declared unconstitutional in 1952.

"The goals articulated by the government - to prevent aliens from absconding or endangering the community - only justify detention of those individuals who present such a risk."

As a warning demonstration (and perhaps to prevent other aliens from coming), the Galaxy Being destroys the transmitter tower.

The program was originally established in 1997 as the Basic Pilot Program along with two other programs created to prevent illegal aliens from getting jobs.

The main character, portrayed the Dack Rambo, is looking for zirconium which is used to make bombs to prevent aliens from destroying Earth.

It was created to prevent criminal aliens from being released into the general public.

In Arizona, vigilante-like Minutemen have staked out the border to prevent illegal aliens from crossing into the United States.

They said it would be tragic if any confusion about possible extensions prevented eligible aliens elsewhere from applying.

Preventing criminal aliens from returning, officials said, is the final Sisyphean task.