Piazza grew up in Livermore, California and attended Livermore High School, where he was a varsity athlete. He later became a doctor of chiropractic and owned a practice in California.
Through lectures and presentations, he relates the story of the evening his home was the target of a random drive-by shooting. Escaping injury, he realized that the firearms he owned did him little good as he had no real training in their use. He made the decision to become the best he could be in the defensive use of his firearms, and wanted to teach others how to do the same. Ultimately, this led to his founding of Front Sight near Bakersfield, California in 1996, to "positively change the image of gun ownership in our lifetime".
In 1998, his concept expanded to include a complete "world-class" resort, like a "Disneyland for gun enthusiasts" and a town, Front Sight, Nevada, envisioned as "the safest community in America". Since this time, he has been working to build this resort about 45 minutes outside of Las Vegas, Nevada. His efforts have been covered by local news and gun enthusiast periodicals, but notably have received international exposure as well in the New York Times, Chicago Tribune, LA Times, BBC, Playboy Magazine, USA Today, San Francisco Chronicle, CNN, Washington Post, Forbes, and a piece by Diane Sawyer.
Piazza established a philanthropic project called Helping Those Who Help Others. The stated goal of this project is to focus on and contribute to charities with a proven track record, similar to a charitable trust. A list of charities which have been supported can be found at the project homepage.
In 2003, Piazza produced a documentary entitled Innocents Betrayed. The purpose of this documentary was to show the point of view that, historically, gun control has been used to disarm populations for the purpose of government sponsored genocide.
He created and began producing the reality television series Front Sight Challenge, airing on the Versus Network in 2006. Front Sight Challenge is now available for online viewing.
Through Front Sight, Piazza was involved in preparing actor Mark Wahlberg for his role in the 2007 film Shooter.
Piazza has been dubbed Millionaire Patriot for providing millions of dollars in firearms and training to help citizens protect themselves and their families.
Piazza is a life member of Keepandbeararms.com and the NRA, although he disagrees with some of the NRA's methods and certain positions on some issues. For instance, Piazza does not agree that the message of gun ownership should be watered down by claiming that guns are only for hunting, a claim to which anti-gun activists may respond by asking why someone needs an AK-47 to shoot a deer; he believes that the simple and honest message that firearm ownership is protected by the 2nd Amendment is enough (reference: Front Sight promotional DVD, 2005).
In November 2009, in response to the Fort Hood shooting, Piazza gave away 500 AK-47-pattern rifles with the purchase of a $995 Front Sight Lifetime Membership.
Piazza was among the first to respond to the September 11, 2001 attacks with suggestions on how to prevent this type of event from happening in the future. His proposed solution was to arm all airplane pilots, and to this end he promised free training to all airline pilots in his "Arm Our Pilots Campaign". At the time this was viewed incredulously in some circles, but has become a more plausible response in political discourse with the passage of time. Piazza takes pride in being a leader in promoting this type of answer to violence and terrorism (reference: Front Sight promotional DVD, 2005).
In April 1999, in response to the Columbine High School massacre, Piazza announced that free firearms training would be offered for up to three teachers or administrators at any school in the United States.
As a response to the Virginia Tech massacre in April 2007, Piazza announced that free firearms training would be offered to any teacher, administrator, or other school staff member designated as school safety monitor.
In 2007, University of Utah lifted the ban on students carrying concealed weapons. Piazza announced that a 5-day course on carrying and using a concealed handgun would be offered free to every student there. Having taken this course and received a concealed carry permit, any Utah student would be able to carry concealed in 30 US states due to reciprocity laws. Furthermore, the student's diploma from the university would carry the designation CWP (concealed weapon permit). Piazza stated, "If our university students are old enough to fight for our freedom and die in Iraq with a machine gun in their hands, then with Front Sight’s responsible training under their belts, they are certainly old enough and intelligent enough to carry a concealed handgun on college campuses to protect themselves, classmates, and faculty from the next homicidal and suicidal psych drug failure."
Piazza was previously granted a special deputyship by the Nye County, Nevada sheriff, a fairly common practice in rural counties. This commission was rescinded in light of new county laws by newly elected county sheriff Tony DeMeo in 2003.
In 2002, he sued former Front Sight instructor Dean Gamburd for libel. The basis of the suit was literature which Gamburd had distributed linking Piazza and Front Sight to Scientology. The case was apparently settled.
That same year, Front Sight, Inc. and Piazza individually sued Diana Hsieh for libel. The case was settled out of court. This lawsuit was in effect a complaint that Diana Hsieh had linked Front Sight with Scientology in a manner which Piazza believed to be unfair. The complaint accused Hsieh of linking the company to "hateful, bigoted and untrue statements" concerning Scientology.
In 2006, Piazza and Front Sight were sued in a class action by certain members of the "First Family", an exclusive membership to the Front Sight facility, for failing to deliver on expectations made when the memberships were purchased.