For a program that the White House has never officially acknowledged, the use of missile-laden drones to strike suspected Muslim militants hardly remains a secret.
Even so, while pledging to protect Americans around the globe in his State of the Union address Tuesday, President Barack Obama never used the "D" word -- or what the military calls unmanned aerial vehicles.
"Where necessary, through a range of capabilities, we will continue to take grave action against those terrorists who pose a threat to America," Obama said, offering no other details.
Beyond the White House, however, the topic of drones is getting plenty of attention.
From pointed questions from members of Congress to grass-roots resistance movements around the country, drone warfare in Pakistan, Yemen and Somalia has come under increasing scrutiny.
The widening debate has focused on moral and ethical concerns surrounding "kill lists" as drone strikes are planned by the Air Force and the Central Intelligence Agency, the legality of drone attacks under international law when war has not been declared, and the expansion of executive power.
"It's a conversation the country needs to have," said Morris Davis, assistant professor of lawyering skills at Howard University's School of Law.
"I think it's been a real disservice by Republicans and Democrats alike (to fail to address drones). The only thing we've really found out about the drone program ... has been through leaks. It hasn't been through the government informing us about what's being done in our name," Morris told Catholic News Service after a presentation on torture Tuesday at the annual Catholic Social Ministry Gathering.
Despite the president's unwillingness to discuss the drone program, some in the administration have addressed it.
"These strikes are legal, they are ethical and they are wise," White House press secretary Jay Carney told reporters Feb. 5 after a Justice Department white paper outlining the legal argument for targeting U.S. citizens working in suspected terror networks overseas was leaked.
In a series of interviews in early February before stepping down as defense secretary, Leon Panetta maintained that drone strikes are necessary to keep the country safe. As CIA director from 2009 to 2011, Panetta authorized about 200 drone strikes in Pakistan under rules drafted early in the Obama administration.
"I think we had a responsibility to use whatever technology we could to be able to go after those who not only conducted that attack (on 9/11) but were planning to continue to attack this country," he told Agence France-Presse.
Panetta, who is Catholic, acknowledged in an interview with National Public Radio that his task was not easy.
"As a Catholic, suddenly realizing that I had a responsibility of saying we're going to have to kill somebody was something I did not take lightly," he said. "It's a heavy responsibility."
Such decisions since 2004, the earliest days of the drone campaign, have led to thousands of deaths, innocent victims included. Although the administrations of Obama and former President George W. Bush have declined to release casualty figures, the New America Foundation has tracked drone strikes and the resulting loss of life.
Through Feb. 11, the foundation said an estimated 351 strikes claimed between 1,944 and 3,263 lives. While the vast majority of deaths are believed to be suspected militants, civilians, including women and children, are included in count.
The findings show that drone strikes escalated rapidly under Obama after he took office in 2009. Under Obama 255 strikes have occurred compared with 48 under Bush, the foundation said.
The loss of innocent life concerns some Catholic observers. Identifying suspected militants based on observed suspicious activity from thousands of feet in the sky is problematic, they said.
Charles Camosy, assistant professor of Christian ethics at Fordham University, advocated framing drone warfare as a pro-life issue.
"It involves violence and violent killing. It involves the killing of the innocent in a way that doesn't follow the church's teaching. It's an exercise of raw violent power in a way that I think should get pro-lifers really, really upset," Camosy said to CNS.
Marie Dennis, co-president of Pax Christi International, suggested that drones have led to "a battlefield without borders."
"We have a global battlefield, which completely undercuts any possibility of talking about just war. There are no boundaries on this thing," she said.
Through its increasing dependence on drones the U.S. has set itself up to be engaged in a "perpetual state of war," said Gerard Powers of the Kroc Institute for International Peace Studies at the University of Notre Dame.
While acknowledging that the U.S. has a moral obligation to protect the country and to avoid placing soldiers at unnecessary risk, Powers questioned whether the use of drones to attack suspected terrorists fulfills just war criteria.
"Does the use of drones make it easier to go to war because there's no risk? If it makes it too easy to use force, too easy to drop bombs, too easy to go to war, then that's a concern," Powers said.
Two years ago the U.S. Conference of Catholic Bishops' Committee on International Justice and Peace encouraged the White House to review the use of unmanned drones.
The suggestion came in a letter April 6, 2011, on the country's transitioning role in Afghanistan to Thomas Donilon, Obama's national security adviser. Bishop Howard Hubbard of Albany, N.Y., then the committee chairman, acknowledged  that the U.S. must continually review the use of military force in Afghanistan and "whether and when force is needed to protect the innocent and resist terrorism."
Addressing the consequences of the drone strikes in noncombatant countries, Michael Boyle, assistant professor of political science at La Salle University, told CNS the U.S. risks driving people into militant ranks.
"Does the president have the right to be judge and jury and executioner for terror suspects? There is no presentation in a court, no congressional oversight, no ability for a person to defend themselves," Boyle said.
In a lengthy analysis  in the January issue of International Affairs, Boyle suggested that the use of drones is not as effective as Panetta and others claim. The U.S., he wrote, "is encouraging a new arms race that will empower current and future rivals and lay the foundations for an international system that is increasingly violent, destabilized and polarized between those who have drones and those are victims of them."