Visible crew/equipment: When Dr. Okun is about to unlock "the vault", and says, "The freak show," a crewmember wearing a black and white striped shirt is hiding under the vault's floor, right behind Okun. (Only visible on fullscreen DVD.)
Visible crew/equipment: At the White House, when they all watch the Soviet Special News, in the close-up of the TV's staticky reception of the news feed the reflection of White House staffers is visible. Right between the woman in a white blouse and the man in suit and tie, is the camera and crewmember, wearing a light-colored short sleeve shirt and baseball cap, moving about. (00:15:20)
Visible crew/equipment: When David reaches Connie on her cell phone in the White House, as she walks away away from the wall to head towards the window, a crew member (complete with water bottle and utility belt) can be seen on the lower left portion of the screen, before he quickly scrambles away. (Only visible on VHS and fullscreen DVD.) (00:38:27)
Visible crew/equipment: When President Whitmore returns to the containment lab to see the live alien, just as Major Mitchell and a Secret Service Agent walk to face the smoke filled lab, the actor's mark is visible on the ground as the Agent steps up to it. (Only visible on fullscreen DVD.)
Visible crew/equipment: After Dr. Okun unlocks "the vault" he explains the aliens' telepathic ability, and as David steps closer to the tanks the actors' marks are visible on the floor. (Only visible on fullscreen DVD.)
Visible crew/equipment: When Dr. Okun leads President Whitmore, General Grey, David and the rest to see, as he put it, "The big tamale," the red actor's mark is visible at the top of the landing as they all walk up the ramp. (Only visible on fullscreen DVD.)
Visible crew/equipment: In the containment lab, when the alien awakens and begins its attack, the alien moves from right to left towards a doctor, who is backed up against a door. The crewmember who is wearing the alien costume has on a white shirt and black trousers, and the costume's straps attached to the pants are visible, as well as some wiring at the back. (Only visible on fullscreen DVD.)
Visible crew/equipment: At Area 51's main research facility, Dr. Okun walks up to greet President Whitmore and as his assistant, Dr. Isaacs walks up behind him, the green actor's mark is visible on the floor - he even glances down at it. (Only visible on fullscreen DVD.)
Visible crew/equipment: At the containment lab, just before Dr. Okun unlocks "the vault", three actors' marks are visible. One mark is at the top of the ramp and the other two are visible just past the ramp. (Only visible on fullscreen DVD.)
Visible crew/equipment: At the Area 51 lab, when President Whitmore is down on the ground in pain, in the shot from inside the lab facing the lab's outer hall, the alien costume only reaches just above the crewmember's waist - the costume straps attached to his pants are visible, as well as his arm. (Only visible on fullscreen DVD.)
Visible crew/equipment: When President Whitmore, General Grey and the rest return to the containment lab to see the live alien, Major Mitchell stands directly in front of the smoke filled lab and the camera equipment/crew are visible in the reflection on the glass. President Whitmore, General Grey and a few others are supposed to be the only ones in front of the three aliens' liquid chambers. (Only visible on fullscreen DVD.)
Visible crew/equipment: After Steven and David return, when President Whitmore walks over to David reflections of the reflector screen are visible on the President's sunglasses.
Visible crew/equipment: On bended knee, when Jimmy opens Steven's gift box with the ring, in the close-up an oblong metallic object is pushing up against Jimmy's left hand, between his thumb and index finger. Likely used to keep his hand steady in the tight close-up. (Only visible on fullscreen DVD.) (00:35:20)
Visible crew/equipment: When the alien is inflicting pain upon President Whitmore telepathically, in the shot from inside the lab facing the outer hall, through the glass, General Grey's mark is visible on the floor. (Only visible on fullscreen DVD.)
Visible crew/equipment: After the President and the rest return to the containment lab to see the live alien, when Major Mitchell is standing in front of the smoke filled lab, a piece of equipment is seen moving about at the bottom of the screen. (Only visible on fullscreen DVD.)
Visible crew/equipment: After President Whitmore decides to go ahead with David's plan for the virus, he, Connie and Grey are walking when the President pushes Nimzicki up against a desk. Just before they reach that desk, the actor's mark is visible on the floor, precisely where the President stops before he fires Nimzicki. (Only visible on fullscreen DVD.)
Visible crew/equipment: When President Whitmore is on the phone with his wife (their daughter Patricia lies on the bed), telling her he wants her to leave LA and a chopper will take her to Nellis Air Force Base, a Secret Service Agent appears at the doorway and the actor's mark is visible on the floor. (Only visible on fullscreen DVD.)
Visible crew/equipment: When Steven is about to leave for El Toro, just as he walks up to his red car, where Dylan plays, the actor's mark is visible on the ground before he steps up to it, and before Jasmine joins him beside the car. (Only visible on fullscreen DVD.)
Visible crew/equipment: When David introduces the idea of a virus, the first time Major Mitchell shoots at the Coke can the two actors' marks are visible on the floor in front of Julius and Connie, as well as a brown rug at their feet, that are not in other shots. (Only visible on fullscreen DVD.)
Visible crew/equipment: At the club, when Jasmine walks to the mirror in the dressing room her tape mark is visible on the floor. (Only visible on fullscreen DVD).
Answer: Remember that the aliens had to interface with our satellite computer code first...David simply "reverse engineered" the code to create the virus. When it was uploaded, they didn't have enough time to combat it.