Pakistani news reports have quoted authorities as saying that 708 civilians were killed in U.S. drone strikes in 2009 alone. The Long War Journal, a website that uses news reports and contacts with security sources in Afghanistan and Pakistan to track drone strikes, puts the number at 43, and a cumulative 94 since 2006. It estimated that more than 1,100 militants were killed last year in such aerial attacks.

People whose families suffered casualties were interviewed outside the tribal areas. In each case, local or national Pakistani authorities, speaking on condition of anonymity, verified that a drone strike had taken place. Many of those interviewed said they simply didn't understand why their relatives were hit.

Shakir Khan, 22, a wiry grocer with a patchy black beard and piercing brown eyes, said Taliban militants freely roamed the dirt lanes of his village, Gangi Khel, in summer 2008 when the missile hit his home. They strode through town like self-appointed marshals, bandoleers slung across their shalwar kameez tunics, long black hair flowing out from their Pashtun caps.

But no one in Khan's family has any ties to the Taliban, he said in an interview in Kundian, about 80 miles from the Waziristan border, and militants never visited his house. All the same, his nephew Zeerak and niece Maria were killed. Irfan, another nephew, has been mired in a deep depression.

Five of their 12 rooms are still sufficiently intact for Khan, his three brothers and their families to live there. Shakir is angry that the family has suffered despite keeping a distance from the militants.

"If Americans think that everyone who prays five times a day is a militant, they're wrong," Khan said. "They kill us without any reason. If they know about Taliban or Al Qaeda, OK, be specific and attack and kill them. But don't kill innocent people."

Drone strikes are not the only risk in the tribal areas. Al Qaeda and the Taliban have responded to the aerial assaults by stepping up assassinations of residents accused of providing targeting information to Pakistani or U.S. intelligence agencies, researchers say. Attacks and assassinations by militants, and air and artillery strikes by the Pakistani military, actually kill far more civilians there than the drones, Pakistani researchers say.

Khadim Hussain, coordinator at the Aryana Institute for Regional Research and Advocacy, an independent think tank in Islamabad, the Pakistani capital, that studies issues affecting the tribal areas, said residents of the tribal areas objected to the militants' influence on their lives.

"Many of them told us they would like these bastards to be killed, but would like the Pakistani state to do it,'' Hussain said. "They say they're unable to dance their traditional dances, or assemble without the permission of the local militant commander. These things trespass on their honor code, their lifestyle and their culture."

In a poll of 550 tribal area residents by the institute last year, 58% said drone attacks did not foster anti-American sentiment. Fifty-two percent said the strikes were accurate, and 60% said they damaged insurgent groups. Farhat Taj, an anthropologist who grew up in the area, said residents of some tribal areas aren't concerned about drones violating Pakistani sovereignty because Pakistan doesn't exercise control there, anyway.

In some tribal areas that have not been targeted, such as the Malakand district of the North-West Frontier Province, residents have requested drone attacks against local militants, said Samina Ahmed, project director for the International Crisis Group in Islamabad.

Some analysts say that not all civilians are equally mourned. The strike that killed Taliban leader Mahsud, for instance, also killed his wife and her parents. Family members perceived as helping militants are not much mourned, particularly if they are Arabs or other outsiders, some researchers say.

"It sounds callous to say, but it's not the same as when innocent local bystanders are killed," said Bill Roggio, founder of the Long War Journal.

In some villages, though, Taliban militants are native sons.

Many of the boys that Zaman Khan grew up with in the South Waziristan town of Shakai eventually joined the Taliban. He knew they had become militants, but he never thought it odd to have them over for tea.

Whether it was because of Taliban visits or the proximity of a regular Taliban meeting place 30 yards away, Khan's house became a target March 15, 2008.

The missile struck while everyone slept, killing Khan's brother, Wazir Khan, 40; Wazir's wife, Zara Bibi, 30; and their 4-year-old son, Irshad. The left half of Wazir's body had been sheared off. Zara's and Irshad's bodies were charred from head to toe.

Wazir's two other children, Noor Rehman, 10 at the time, and Ishaq Khan, 3, survived. Physically, they recovered but suffer from psychological problems, Zaman Khan said.

"Ishaq doesn't talk at all," Khan said. "He can't recognize his family, and he drinks only if someone helps him."

Three weeks after that strike, a house full of civilians in the same neighborhood was struck, instantly killing cousins Sher Maan, 20, and Azeem Ullah, 30, and Azeem's wife, Gul Anama, 25.