In the film, NYPD Detective John McClane (Bruce Willis) attempts to stop a cyber-terrorist, Thomas Gabriel (Timothy Olyphant) who hacks into government and commercial computers across the United States with the goal of starting a "fire sale" cyber attack that would disable key elements of the nation's infrastructure.

It is the only Die Hard film to be theatrically released with a PG-13 rating from the MPAA, although an unrated edition would later be made available on home media.

On the way to Washington D.C., Farrell tells McClane he had written an algorithm for Mai Linh to crack a specific security system for white hat purposes.

Meanwhile, Gabriel orders his crew of hackers to take over transportation grids and the stock market while nationally broadcasting a threatening message to the U.S. government.

He warned the department of weaknesses that made America's network infrastructure vulnerable to cyberwarfare, but he was ignored and his unorthodox methods got him fired, and he is out for revenge.

Enraged over Linh's death, Gabriel redirects the natural gas pipelines to the superstation to kill McClane and Farrell, and they barely escape before a massive blackout occurs throughout the Eastern Seaboard.

Warlock identifies the piece of code Farrell wrote for Linh as a means to access data at a Social Security Administration building at Woodlawn, Maryland.

The Woodlawn building is actually an NSA facility intended to back up the nation's personal and financial records in the event of a cyber attack and was designed by Gabriel himself.

Accessing the communication system of an F-35B Lightning II, Gabriel orders the pilot to attack the truck McClane is driving, but the jet is destroyed by falling debris.

Additional characters include Gabriel's henchmen: Chris Palmero as Del, Andrew Friedman as Casper and Bryon Weiss as Robinson.

Matt O'Leary appears as Clay Wheeler, a hacker who unwittingly gives Gabriel a code, allowing his house to be destroyed.

The script was about a group of people who go to set up a radio relay station deep inside the Amazon jungle, but due to a severe storm, they land in a small mining town where they hire a guide.

Along with McElroy, other writers who worked on the script included Ronald Bass, Chris Gerolmo, Larry Ferguson, Robert Mark Kamen and Joel Gross.

[16] Using John Carlin's Wired magazine article entitled "A Farewell to Arms", Marconi crafted a screenplay about a cyber-terrorist attack on the United States.

After the September 11, 2001 attacks, the project was stalled, only to be resurrected several years later and rewritten into Live Free or Die Hard by Doug Richardson and eventually by Mark Bomback.

[21] 20th Century Fox later announced the title as Live Free or Die Hard and set a release date of June 29, 2007 with filming to begin in September 2006.

[22][23] The title is based on New Hampshire's state motto, "Live Free or Die", which is attributed to a quote from General John Stark.

[25] For the visual effects used throughout the film, actor Bruce Willis and director Len Wiseman stated that they wanted to use a limited amount of computer-generated imagery (CGI).

The shot was completed when the two characters were integrated into the footage of the car stunt after the lighting was adjusted and CGI glass and debris were added.

[28] The Orphanage developed a multi-level freeway interchange for use in one of the film's final scenes by creating a digital environment and a 1,000-foot (300 m) long spiral ramp that was built in front of a bluescreen.

[29] When the jet is shown hovering near the freeway, editors used the software 3D graphics program Maya to blur the background and create a heat ripple effect.

[33] Willis was injured on January 24, 2007 during a fight scene, when he was kicked above his right eye by a stunt double for actress Maggie Q who was wearing stiletto heels.

[32] Bruce Willis' stunt double, Larry Rippenkroeger, was knocked unconscious when he fell 25 feet (7.6 m) from a fire escape to the pavement.

Other songs in the film include "Rock & Roll Queen" by The Subways, "Fortunate Son" by Creedence Clearwater Revival and "I'm So Sick" by Flyleaf.

[42] In Australia, Die Hard 4.0 was released with the PG-13 cut with an M rating, the same as the others in the series (The Australian Classification Board is less strict with regards to language and to a lesser extent, violence).

[52] Mike Dunn, a president for 20th Century Fox, stated "The industry has sold nearly 12 billion DVDs to date, and the release of Live Free or Die Hard is the first one that allows consumers to move their content to other devices.

The site's critical consensus reads, "Live Free or Die Hard may be preposterous, but it's an efficient, action-packed summer popcorn flick with thrilling stunts and a commanding performance by Bruce Willis.

[59] IGN stated, "Like the recent Rocky Balboa, this new Die Hard works as both its own story about an over-the-hill but still vital hero and as a nostalgia trip for those who grew up with the original films.

"[61] Michael Medved gave the film three and a half out of four stars, opining, "a smart script and spectacular special effects make this the best Die Hard of 'em all.

"[62] Conversely, Lawrence Toppman of The Charlotte Observer stated: "I can safely say I've never seen anything as ridiculous as Live Free or Die Hard."