Gabriel Byrne's character looks and dresses exactly like Travis Bickle, Robert De Niro's character in Taxi Driver (1976). He also drives Dean away in a taxi.

Boxing is on TV in four separate scenes.

The satellites repeatedly send "CQ" in Morse code every time they're seen. "CQ" is ham radio shorthand for "Anybody out there want to chat?" ("Seek you.")

Both Gabriel Byrne and 'Loren Dean (I)' played major roles in Wim Wenders' The End of Violence (1997), another film that deals with the social perils of techno-surveillance.

Several times the location of a person or vehicle being tracked is given in degrees and minutes of latitude and longitude. Near Washington, D.C., this designates an area of about 1.02 square miles. Not quite as precise as shown.

Tom Sizemore played in a scene in True Romance (1993) in which multiple heavily armed groups of men faced each other at gunpoint in a small room with a shoot-out massacre as result. A similar scene appeared in Saving Private Ryan (1998), also featuring Sizemore. This movie contains another such scene, again featuring Sizemore.

Gene Hackman's character's name (Brill) is very similar to his character in The Split (1968).

The portable video game system that Dean's son uses, and in which "the disc" won't work, is an NEC Turbo Express.

The storm drain car chase scene was shot in a large air duct tunnel below the four main bores of the Fort McHenry Road Tunnel in Baltimore, MD. Fort McHenry permits Interstate 95 to pass under Baltimore's harbor. The air duct is only accessible from the Tunnel's Admin Building by stairs and a small elevator, so the cars in the scene were chopped into several sections, taken three levels below, reassembled and painted. Once filming was complete they were disassembled once again and removed from the duct. The water was hosed in from a nearby sprinkler main.

Seth Green is uncredited.

The sound made by the bug sweepers used in the film is the same as the sound made by the sonar equipment in Crimson Tide (1995), also directed by Tony Scott. Gene Hackman, Jason Robards, and Lillo Brancato were in both films.

Writing credits in the film's early promotional material read "Written by David Marconi and Aaron Sorkin and Henry Bean & Tony Gilroy".

Gene Hackman turned down the film several times, but was ultimately convinced to sign on after a phone call by director Tony Scott. Will Smith later signed on at a relative post-Independence Day (1996) bargain price because he wanted to work with Hackman.

The film's technical advisor, Larry Cox, is a former National Security Agency official.

Director Tony Scott initially turned down producer Jerry Bruckheimer's offer to direct the film.

The mark left on the mailbox to signal Brill is exactly how ex-CIA official and traitor Aldrich Ames signaled the Soviets when he made a drop.

Thomas Reynolds' birth date is given as 9-11-40. On 11 September 1940, Bell Labs researcher George Stibitz demonstrated the first remote operation (i.e., over a phone line) of a computer machine.

When Brill accesses the National Security Administration's executive files to identify Reynolds, the very first photograph that flashes from the personnel files has the name "Buster, Ball" below it.

Tom Cruise was originally signed on to star in this film, but had to turn it down because he was still filming Eyes Wide Shut (1999).

The building that serves as Brill's workplace is actually originally a Dr. Pepper plant.

The Ruby lingerie store is actually the doctored store front of Lambda Rising, a well-known gay bookstore on Connecticut Avenue in Washington, DC.

The latitude/longitude given during the chase are actually the location of the real CIA headquarters in Langley, Viginia.

Mel Gibson was also considered for the role of Robert Clayton Dean.

The picture of a younger Gene Hackman shown in a white shirt and tie, supposedly from his NSA file, is actually taken from The Conversation (1974). In that film Hackman also plays a surveillance expert who, like his c

Continuity

At the end of the film when Dean sits down and switches on the TV he sees himself from a camera in the smoke detector but when he looks at the TV, the angle of the camera is positioned from the TV as he is looking straight forward.

When Brill and Dean are breaking into the Congressman's hotel room, the footage used of Dean waiting by the door is reused from the footage of Dean waiting for Mr. Wu to open the door. The footage is used twice during the break-in within a few seconds. Dean is wearing a tie and dress overcoat while waiting for Mr. Wu, while not wearing a tie nor dress overcoat when breaking in with Brill.

When Dean and Brill are outside the police station near the end, a glimpse of the sky shows thin clouds and blue sky. Moments later while Brill is running away and is intercepted by the goons in the car it is pouring rain.

When Dean is in the goons' van, Lyle is escorted to the back of the van, sheltered from the pouring rain under an umbrella. While he enters the van, the rain is pouring down behind him, yet in a close-up of Reynolds, the city skyline can be seen over his left shoulder with not a drop of rain in sight.

During the rail yard scene, Brill punches Dean and the camera shot briefly changes to Dean crouching. Before and after this shot there is a moving train behind Dean, during the shot there is an empty track.



Factual errors

When Dean is running on the hotel roof after Brill leaves him, the surveillance team reports that the satellite is coming on-line with "one meter resolution". One meter resolution indicates that the smallest pixel (detail) that can be seen is 1 meter by 1 meter while the film clearly suggests that the satellite has enough resolution to see Dean running. Assuming you would need at least "web-cam" resolution (75 pixels-per-inch), the satellite resolution would need to be roughly 2,800 times higher than one meter (38 inches x 75 pixels per inch = 2,850).

It is impossible to obtain a 3D image of the shopping bag (or anything) from one camera feed that the investigators had. Supposing that they had another camera in the store, they would simply have two images from different points of view but the rotating p.o.v. still cannot be achieved this way.

The reporter says that a bottle of pills was found in the lap of Senator Hammersley. The assailant dumped the pills and bottle in the seat, and the car was submerged. The pills would have dissolved or, at the least, floated away, and the senator was left prone in the seat making it all but impossible that the bottle would remain in his lap.

OSHA standards for cleaning supplies, as in the cleaning supply closet at the hotel, specifically forbid flammable cleaning supplies for the very reason that Dean proved: a fire hazard. Moreover, it would be incomprehensible that any hotel with even the smallest degree of safety precautions would even think about keeping lighters, ashtrays and flammable liquids anywhere near one another.

One of the operatives remarks that the global positioning satellites have an orbit of 155 miles. Such a low-earth orbit for a satellite would be entirely impossible, as it would not be stable at such a low altitude for very long (perhaps two weeks at most). Normal altitudes for GPS's and other earth-observing satellites are at least 600 to 900 Kilometers (372 to 562 miles), and more often these satellites orbit from altitudes of 1,000 miles or more.



Incorrectly regarded as goofs

The FBI guy says, "Get some IDs on these guys and get these guys out of here." Proper procedure would prevent the bodies from being moved until forensics had gone over the scene and photographed everything.

When Dean and Brill enter the "jar" in Brill's home, they close the outer cage door with the cat outside it. But they don't close it tight, and the cat is seen forcing her way in, so when the cat is seen later, it's not unexpected.



Revealing mistakes

Near the beginning, when the very powerful spy satellite is brought into use, one scene shows that there is a layer of high clouds, probably cirrostratus. Although high clouds can be translucent to the sun, there is no way the satellite could get a crystal clear view of people running around at the surface. Even awesome technology could not accomplish this. It is obviously a visible image because there is full color.

Obvious stand-in for Dean when the government tech shows the security camera tape of the encounter with Dean and Zavitz in the lingerie store.

When Dean arrives home for the first time, his wife's dog snarls at him. Just before the snarl, the elastic band holding the dog's mouth back to expose his fangs can be seen.

When the team is wiretapping Dean's house, the screwdriver is seen running counterclockwise to screw the air duct register back in. However, the screws are right-hand threaded, so the clip was played backward to produce the film.

When Dean drops down into the tunnel in his robe and almost gets hit by a car, his rather visibly overweight body double can be seen in his place as the car swerves to avoid hitting him.



Miscellaneous

Towards the end, Robert, Carla, and son are watching TV after dinner. Carla says it's time for their son to go to bed, but Robert tells him to eat his dinner. Will Smith's ad-lib doesn't match what is happening.



Anachronisms

Brill tells Dean about his experiences with the Iranian secret police aid the Afghan rebels against the Russians, then mentions the U.S. Embassy seizure in Iran. But the Embassy was seized in November 1979, one month before the Soviet invasion of Afghanistan (December).



Audio/visual unsynchronized

When Thomas Reynolds and wife are checking their bank statement for the extra $140,000, Reynolds says, "Two separate $70,000 deposits on the same day." The statement, however, shows the dates of the deposits as 12/09 and 12/11.

When Dean is talking to the cat, the cat seems to 'answer' him with a meow, but his mouth doesn't open.



Errors in geography

In different scenes supposed to be in Baltimore, satellite surveillance is requested first at latitude 39?14', longitude 74?39'; then at latitude 39?27', longitude 74?42'. Both positions are about 100 miles east of Baltimore near Atlantic City, NJ, one of them actually in the ocean. The correct longitude for the first location, for instance, would be around 76?37'.

When the NSA agent watching Brill's vehicle on the Satellite imagery dispatches the NSA "hit team" to Brill's secret location (the "Jar") he tells them to proceed to Latitude 30 degrees, 64 minutes and Longitude 72 degrees, 29 minutes. Not only is this an incorrect syntax to identify a location using that nomenclature, it also places Brill's location about 547 miles east north east of Jacksonville, Florida at a spot in the Atlantic Ocean.

In a Baltimore scene, the technician requests surveillance at latitude 30?64', longitude 72?29'; There are 60 minutes in a degree, so this is like expressing a person's height as 5 feet 14 inches; he obviously misspoke. Yet the reply is simply "Affirmative", without question or request for clarification. Also, the coordinates are not near Baltimore.

In Congressman Albert's home address, the city is shown as "Lake Falls, Maine", but the ZIP code is 20015, which would be in Washington, DC.

When Zavitz begins to flee, satellite surveillance is heard to be requested at latitude 38?55', longitude 77?00'. That exact position would be around 4th and U Streets Northeast, and giving the coordinates to the minute implies an accuracy of about a mile (a nautical mile, in fact, around 1.15 miles or 1852 meters). Moments later, as he reaches the roof, the street intersection is given as 18th and Columbia, which is in Washington's northwest quadrant, more than 2 miles away.



Plot holes

When Dean's wristwatch is being switched, the replacement watch has a brand new leather strap. Any person using this kind of strap would immediately notice this, due to normal wear.

When Dean instructs the nanny to intercept Eric and his friend on the way to school, the time on Dean's watch is in the afternoon, not a school-start time.

The character played by Seth Green does not appear with the NSA team at any point after Dean escapes pursuit in the freeway tunnel. No reason is given for his departure, and it seems unlikely he would simply be allowed to leave without comment given the nature of the operation.

While observing the maid, Fiedler comments on the fact that she doesn't shave her legs. When she gets out of the SUV, she's wearing slacks.



Character error

Fiedler researches the relationship between Dean and Banks. First in the list of common items is their attendance at Georgetown University where the record shows they both have the exact same student number.

When Daniel Zavitz retrieves his camera from the hide, he walks past some kind of accident that has occurred. Yet he seems indifferent to the possibility that he could have captured the accident on tape.

Daniel Zavits's camcorder is described as a motion-activated digital video camera by the NSA, yet a close-up of it in the previous scene shows the Hi8 logo. In 1998, only analog signals could be recorded on Hi8 tapes; Digital8 was not introduced until the following year. So it is not a digital video camera.

In the lingerie shop, Dean tells the saleswoman his wife's breasts are "way bigger" than hers. Later, when talking to his wife in the back shed, he opens her bathrobe revealing her to have very small breasts.

When the conspirators are inspecting the security camera footage of Dean's shopping bag, Fiedler tells the tech to rotate the image 75 degrees around the Z-axis, but the image rotates about 110-120 degrees.