Richard Marcinko is the founder of SEAL Team Six and the author of Rogue Warrior and Vengeance.
A SEAL team is a U.S. Navy commando group.
Library Journal wrote:
- Marcinko's participation in the Iran hostage rescue attempt in 1980 and the U.S. invasion of Grenada in 1983 provide a perspective vastly different from the accepted versions of these events. 
Richard Marcinko said:
- SEALs are basically a bunch of social misfits who make music together. They challenge systems. They've got to be challenged, or they get in trouble. 
Marcinko is the author of Vengeance, a book about terrorism and counterterrorism:
- Vengeance is certainly a play on demonstrating the holes that are apparent in homeland security. Now, is it fiction or prediction? I've predicted things that have happened in the past, including an airplane-run way ahead of 9-11. How? Because I know the terrorist mind. I think like a bad guy. This new book does look at vulnerabilities. It does embarrass the bureaucratic system, but not the people in the field who are either not trained or not equipped. 
After following orders to test Marine and Navy security, "... he reportedly embarrassed several superior officers, whom he accuses of involvement in his subsequent conviction for misappropriation of funds and resources under his command." 
- Beyond the DropZone - W. Thomas Smith, World Defense Review
- Amazon review - this is the best account of the Rogue Warrior book