RAFAH, Gaza Strip -- When Fadel Shalouf's family went to pick up his body at the morgue the day after he was executed on a busy Gaza street corner, they found his hands still cuffed behind his back. Hamas, the militant faction that rules Gaza, did not provide a van to carry the body to burial, so they laid him on two men's laps in the back of a sedan.
It was an undignified end to a short, shrouded life. Mr. Shalouf, his family insists, was an illiterate fisherman with a knack for designing kites when he was arrested by Gaza's internal security service. Yet he was convicted in a Hamas court in January 2011 of providing Israel with information that led to the 2006 assassination of Abu Attaya, commander of the Popular Resistance Committees.
During last month's intense eight-day battle with Israel, the military wing of the Hamas government brutally and publicly put an end to Mr. Shalouf, 24, and six other suspected collaborators. The vigilante-style killings by masked gunmen -- with one body dragged through a Gaza City neighborhood by motorcycle and another left for crowds to gawk over in a traffic circle -- highlighted the plight of collaborators, pawns preyed on by both sides in the long-running Israeli-Palestinian conflict.
"Fadel lived poor and died poor," said his cousin, Ahmed Shalouf, 28. "They left the bodies for a few hours in the streets, people spitting on them, throwing stones. They did not execute only Fadel, they executed all of us."
For Israel, despite its advanced technology for tracking terrorists, human sources remain an essential intelligence tool that allows for pinpoint strikes like the one that felled Ahmed al-Jabari, operations commander of Hamas' Al Qassam Brigades, at the start of the recent escalation. To Hamas, they are the enemy within, and vigorous prosecution plus the occasional high-profile lynching are powerful psychological tools to enforce loyalty and squelch dissent.
Former intelligence officials and experts on the phenomenon said many collaborators are struggling souls who are blackmailed into service by an Israeli government with great leverage over their lives. Some are enlisted when they apply for permits to seek medical treatment in Israel, for example, or in exchange for better conditions or early release from Israeli jails. Others are threatened with having behavior shunned in their religious Islamic communities -- alcohol use, perhaps, or adultery -- exposed.
"There is no substitute to a human source, because a human source goes into their house, sometimes even into their minds," said Yaakov Peri, a former head of the Shin Bet, Israel's domestic intelligence agency. "With all the technology -- drones, you name it -- you need a background, and you need the assistance from a human source."
Mr. Peri said Palestinian collaborators might be given money for expenses or a small salary, but "you'll never be a rich guy."
Collaboration has underpinned Israeli-Palestinian relations since before there was a modern state of Israel, dating back at least to the Jewish underground that operated during the British Mandate era in the 1930s. But while experts on both sides estimated that 1,000 suspected collaborators were killed -- mostly in summary justice -- between 1987, the start of the first Palestinian intifada, and 1994, human rights groups have documented a relative handful of cases since. Of 106 death sentences imposed by the Palestinian Authority and Hamas-run courts since 1995, according to B'tselem, a leading Israeli human rights organization, 40 were for collaboration; through September, six of those had been executed.