He did turn around and scan the lobby, his giant frame effectively hiding La Forge's unauthorized presence in the concierge's kiosk.

The housing was empty, though, and the assault programmer assigned to detecting unauthorized presence failed to find anything significant.

The unauthorized presence of a plane or other vehicle on an active runway, known as "runway incursion," has been a major concern for years.

Security teams would inform the armored beings that they were trespassing, that their unauthorized presence would be regarded as a hostile act unless they surrendered immediately.

Elminster could see no harm in her unauthorized presence.

Every school in the United States will be free of drugs, violence, and the unauthorized presence of firearms and alcohol and will offer a disciplined environment conducive to learning.

Absently, he gazed around the hold, and then realized he was making sure that nobody was watching him--not because of his unauthorized presence here, but because he had been embarrassed by his unanticipated feelings.

When he makes the attempt, Archer is alerted on the command bridge to an unauthorized presence in the shuttlebay.

If you did rescue somebody from the ruins of the robot colony-does it occur to you that they'd be witnesses to your unauthorized presence here?

Sometimes, Anton Chekhov and other fellow students disguised themselves and even wore some makeup, spectacles or a fake beard, trying to fool the regular school staff who checked for unauthorized presence of students.