By the time he reached Turkey after fleeing his hometown of Raqqa, the de facto capital of Isis in Syria, Hassan was destitute and desperate. And so, over his own misgivings, he helped a friend working with western intelligence to pinpoint the location of an Isis jail in exchange for cash.
Hassan, a lanky young man who asked that his real name not be used, warned his contact that the prison was likely to be full of detainees — innocents, kidnapped or jailed by the jihadi group. Days later, it was bombed.
"I went back to yell at the guy," he recalls. "But he just smiled and said, 'To do this work, you have to crush your heart and conscience beneath your boots'."
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That was Hassan's jarring entrance to the murky world of informants who feed intelligence to the US-led coalition trying to defeat Isis. It is a job he continues to do — mostly out of need but partly, he says, because he hopes the more accurate the information he collects, the less often civilians will be killed in strikes.
A cottage industry of intelligence gathering has mushroomed in the past six months, according to interviews with nine Syrians involved. The trend comes as questions are raised about rising civilian death tolls from coalition strikes. Last week, the Pentagon acknowledged that 105 civilians were killed by coalition bombs in the Iraqi city of Mosul in March; residents in Raqqa say more than 30 were killed at a school sheltering families displaced by war the same month.
Despite conflicted feelings — and sometimes outright disdain toward an American-run alliance — more Syrians who fled Isis have turned to this work as US-backed ground forces move to capture Mosul and Raqqa, the crown jewels of Isis's self-proclaimed "caliphate".
"Everyone is now emboldened to work for the coalition. Why? Because people are tired. Some are desperately poor, others just want this to be over," says another informant. "We even have Isis guys — some of them commanders — working with us. They see Isis being defeated and don't want to die with it."
In spite of the number of civilians killed by coalition bombs, Syrians describe the stunning accuracy of the strikes. Two recalled an Isis commander whose apartment was struck with a missile, even as the floors below and above were untouched.
But some blame the casualties on what they say is "looser rules of engagement" by US forces. Other informants also worry that the problem is their own intelligence, whose quality may have deteriorated when networks rapidly expanded as Isis comes under rising pressure and loses swaths of territory.
Isis clamped down or banned the use of mobile phones and internet in areas it still controls, leaving informants scrambling for more sources. As the anti-Isis campaign escalates, informants' handlers — ranging from the US, the UK and France to Saudi Arabia, Jordan and the United Arab Emirates — are demanding more information, more quickly.
"It has got messy. Before, it was more manageable and organised. We knew the timing when people could talk, we knew what kind of information we were going to discuss," says Youssef, another informant who asked that his real name not be used. "These days, we don't know when people can get online or if they can at all."
One man, who leads a crew of informants, recalls lecturing a US contact over a strike that hit civilians. "The Americans said, 'Yes, we hit it,'" he says. "'But who gave us the co-ordinates? We need to strike. If you give bad information, that's on you.'"
Informants describe a three to four-layered network of interlinked cells. It starts with Syrians inside Isis territory and stretches across the border into southern Turkey. Some cross-check the information, including co-ordinates and photographs, and pass it on to a team leader, who deals directly with a foreign intelligence contact.
Some informants suspect their network leaders, motivated by greed or growing demand, are selling the same intelligence to multiple coalition countries, which could make uncertain information appear sounder than it is.
One team leader's subordinates calculated their boss makes $5,000 a month from one coalition government. Those in the two middle layers, also based in Turkey, make between $500 and $2,000 a month. Sources on the ground — who face the biggest risk of being discovered and killed — earn just $100-$300 a month, with bonuses for high-value targets.
All of those interviewed say their main task is tracing muhajireen, Arab or foreign fighters, and high-level emirs, or commanders. They report back any movement and details as simple as what someone ate or wore.
The biggest prize is to hand over an emir's telephone number or that of one of his bodyguards. (Isis has repeatedly banned the use of phones to prevent fighters from being tracked or bugged, yet, apparently, many of its members continue to use them.)
Informants say they communicate by WhatsApp, the messaging application, while their handlers meet in Turkish hotels to trade information. Sometimes foreign intelligence officers provide their teams with equipment but, just as often, informants buy it for themselves.
Youssef says: "We have so much information on local emirs, we know how many hairs they have on their backside. But muhajireen, that is difficult work."
But personal rivalries and revenge may compromise the quality of the information. One informant in Turkey says an Isis contact in Syria sent the number of a member of the group's Hisba, or morality police, with instructions to "give him hell," raising his suspicions of personal vendetta.
The concerns have caused some to claim they are seeking a way out of the business.
"After all the betrayals and all the mistakes I've seen made, I no longer have faith in it," one informant says. "Every day I see things that I think are wrong."