As the world wrestles with the hero-or-traitor conundrum posed by ex-CIA technician Edward Snowden and his bombshell revelations about U.S. government surveillance of citizens’ email and phone traffic, longtime promoters of the whistle-blowing movement — a now-global phenomenon launched by American political activist Ralph Nader in 1971 — are defending the informant ethic as a noble instinct and a crucial check on corruption, corporate malfeasance, excessive secrecy and other abuses of power in modern democracies.