The SPLC has some info on Steve Klein:

Over the past year, Johnson and the church militia have developed a relationship with Steve Klein, a longtime religious-right activist who brags about having led a “hunter killer” team as a Marine in Vietnam. Klein, who calls Islam a “penis-driven religion” and thinks Los Angeles Sheriff Lee Baca is a Muslim Brotherhood patsy, is allied with Christian activist groups across California. In 2011, as head of the Concerned Citizens for the First Amendment, he worked with the Vista, Calif.-based Christian Anti-Defamation Commission on a campaign to “arm” students with the “truth about Islam and Muhammad” — mainly by leafleting high schools with literature depicting the Prophet Mohammed as a sex-crazed pedophile.

Klein, based in Hemet, Calif., has been active in extremist movements for decades. In 1977, he founded Courageous Christians United, which now conducts “respectful confrontations” outside of abortion clinics, Mormon temples and mosques. Klein also has ties to the Minuteman movement. In 2007, he sued the city of San Clemente for ordering him to stop leafleting cars with pamphlets opposing illegal immigration.

http://www.splcenter.org/get-informed/intelligence-report/browse-all-issues/2012/spring/onward-christian-soldiers