Continuity mistake: In the scene after Dade has beaten Kate at the computer game, you see a close up of Kate kissing Curtis whilst sitting on a motorbike. In the background Dade and Phreak walk out of the building and stand on the pavement, and Joey walks up to them and stops. The shot then changes to show Dade and Phreak standing on the pavement, and Joey walks up to them again.
Continuity mistake: Near the middle of the film when Joey gets arrested and is being walked down the stairs outside. If you look in the front halfway down the stairs you can see a guy holding a brown box, but when the camera cuts to a face shot of the black man in front of the camera the man holding the box has disappeared, but he should still be visible because he was only half way down the stairs.
Continuity mistake: Before Dade is about to give Fisher Steven´s character a disk, when he was waiting there is a small water pool on the left side. Dade keeps switching places but in the last change the water suddenly shrinks and becomes about 1/4 size of the original.
Continuity mistake: Just after Joey, Dade, Nikon and Kate finish copying the garbage file onto a disc, Dade reaches inside the booth to grab it. When the camera cuts to the disc, you can see that it is Kate's hand that's grabbing it, not Dade's. You can see a thin black bracelet, long fingernails that are painted white, and a thin silver ring on her thumb.
Continuity mistake: At the beginning when Dade has hacked into the TV network, in one particular shot if you look in the background, you see his 18 today birthday card, note the distance between the card and the TV, then when Dade switches on the TV to watch it, the card has now moved and is standing next to the TV.
Plot hole: When they are on the subway train, they are talking about the worm and the virus. They said that everything would happen on the 14th. A couple of scenes later, when they are setting up for the traffic lights to go crazy at 9:00, Dade looks at his watch. You can see the date as 10-18, which is 4 days afterwards.
Visible crew/equipment: When Dade, Phreak, Cereal, and Joey are sitting at Cyberdelia talking at the table, you can see a shadow of the camera on Dade's face.
Audio problem: When Dade is typing on Kate's computer at the party and she is leaning over her shoulder, we hear "I hope you don't screw like you type", but Kate doesn't actually say 'screw', she mouths a certain 4-letter word that starts with F.
Deliberate mistake: During Dade's first 'hacking' scene, he is wearing sunglasses. The shades disappear for a closeup shot of Dade's eyes and a brief montage of TV clips, then reappear on Dade's face in the longer shot.
Plot hole: If Dade is 18, like we find out at the beginning of the movie when his mom says happy birthday, then his probation is over (the judge said "until the time of your 18th birthday") and the terms restricting computer and phone usage no longer apply. The threats by Secret Service about violating his probation are BS since he's not on probation anymore.
Other mistake: In the scene when 'Gill' is in the restaurant you can see the restaurant worker swipe the bottom of the credit card, rather than the top where the magnetic strip is.
Revealing mistake: In the scene when Joey got busted by the FBI for hacking, he was taking a shower. They then took him to the living room and sat him down on couch with nothing but a towel wrapped around him. As they confiscated Lucy the computer for evidence, he lunged over the couch to try to save her/it. The towel falls off and his butt is in plain view, but his genitals don't exist. Instead, there is a flesh colored pad concealing his privates from the viewers.
Continuity mistake: At the beginning of the film when The Pheak introduces himself to Dade, Joey runs up and says "I need a handle." In this shot we see Joey just put his hand/fingers at the front of The Phreak's shoulder then in the following shot Joey has his whole hand on his shoulder.