Factual error: As the kidnapper is watching TV, we hear a news anchor describing the kidnapped child. She is described as 12 years old, 3 ft. 5 in. tall, and 52 pounds. This is the size of a child half this age. A 12 year old of this size would be freakishly small, which this character is not. And as we see her throughout the movie, she is easily approaching 5 feet tall and in the 70 - 80 pound range. (00:13:30)
Factual error: When Alex & Jezzie are on their chase throughout the city they end up at Union Station. The scene is really filmed at Union Station, however when they go downstairs to get on the train, as instructed, they are no longer really in DC. The train used is not DC's. Platforms are not marked by letters or any other designation in DC and the interior of the train car (layout of seats etc) is that of Baltimore's, rather than DC's.
Factual error: The 'game' set up by Soneji is a whole bunch of computer science-fiction nonsense seen only in movies, with the common factual error of blurry pictures that can somehow be zoomed in ad libitum. The IT agent comments when Cross has clicked on a picture from the camera recording of the class; "Dr. Cross isn't in cyberspace anymore! You're at a live site, looking through a video camera", which does not even make sense. The sequence that follows is not a camera feed, with a real camera being moved, but a panoramic composite shot of the room.
Factual error: During the movie, Senator Rose's daughter is protected by the US Secret Service. A plot point also sanctions that senator Rose is basically a nobody, he does not hold important roles, nor he was threatened in any way before the fact. His daughter would not be under Secret Service protection then, since it is reserved only to the highest elected officials of the nation, not every single relative of every single House member.