Virginia Madsen received a message on her cell phone from Harrison Ford, who was offering her a part in the movie. Madsen thought it was a practical joke at first.
It rained very little during the "rain days" in rainy Vancouver, and so up to six water trucks were used to make "rain" and wet down streets. That was just for two nights making it rain along three whole city blocks downtown. While filming at a luxury house up in Lions Bay for six weeks, the house's roof was covered with rain wands on stands and all the windows had special dripping apparatus all hooked up to a fire hydrant outside the property so we had rain most everyday.
While filming outside Kamloops at the "Cabin" set, Harrison Ford would often borrow the quad ATV from the greens dept, so he could bomb back and forth to set from his trailer without using a driver and van.
When Ravi and Jack are talking about the hacker, the program running on the computer is an open source packet-capture utility called Ethereal. A real network administrator would use that tool (or a similar one) to track an intruder.
The original title for this movie was "The Wrong Element". They soon discovered Kett Turton was going around calling it "The Long Elephant". Offended by this, the producers changed it to Firewall.
On the last days of principal photography at the "cabin" location outside Kamloops, British Columbia, Veronica McAleer, the make-up artist for Paul Bettany invited the crew to show her their scars so she could photograph them for inspiration in building the designs for Bettany's character make up in The Da Vinci Code.
Equifax, one of the most known risk management companies in the world and which is in the New York Stock Exchange, was a special consultant for the film's director, actors and producers.
Re-shoots/filming for additional scenes were done in November 2005 along the shores of Kamloops Lake in Kamloops, British Columbia. The front portion of the house had to be re-constructed because the set builders had torn down the house once filming was completed the previous spring.
The Equifax.com website that is shown in the film is a fully-functioning mock-up of the actual Internet site, created by Equifax webmasters by copying the real site and connecting it to a database containing the credit data called for in the film. Thus, the "look and feel" of the site is absolutely accurate to the real site at the time of the film's release. However, at the request of the film producers, the credit report was embellished somewhat: for example, a real Equifax credit report wouldn't contain gambling debts.
When filming first began at a luxury house in Lions Bay, Harrison Ford decided it would be quicker and more fun to fly up by floatplane instead of endure the traffic due to Olympic preparations on the Sea to Sky highway. This was fine except that the underwriters for the movie insisted that he have a copilot who would be registered as the pilot in charge.
While filming at the Vancouver International Airport, the set was ready for Harrison Ford but he was nowhere to be found. The Assistant Directors went into a frenzy getting all the crew to look for him. He was soon found sitting on the baggage conveyor immediately outside the set going round and round while talking on his cell.
One of the first days filming at the cabin up in Kamloops a crew member was almost bitten by a rattlesnake as he walked along the track to the set. The Assistant Location Manager was called to solve this little problem - as is usual while out on locations. He confronted the snake, picked it up and after showing it around and having his picture taken with it, walked a ways off the traveled path and set it free.
While filming in Vancouver, Harrison Ford took possession of his newest plane, a Citation jet. It was flown up to Vancouver for him. Harrison treated the producers, director, writer and production designer to a flight in his new plane on a scout up to Kamloops.
Harrison Ford was so impressed with the beauty of Bowen Island in British Columbia that he purchased a $13-million waterfront property upon the request of girlfriend Calista Flockhart.
The film deals with a "tiger" kidnapping, this is a crime in which an abduction forms part of a robbery. A person of importance to the victim is held hostage as collateral until the victim has met the criminal's demands.
Of the six characters in the movie who are killed, three of them (Willy, Harry and Vel) are killed by Cox, while the other three (Liam, Pim and Cox himself) are killed by Jack.