The bidding opens at $9,000. For sale? A Yazidi girl. She is said to be beautiful, hardworking, and a virgin. She's also just 11 years old. This advertisement a screengrab from an online marketplace used by ISIS fighters to barter for sex slaves " is one of many Abdullah Shrem keeps in his phone. Each offers vital clues " photographs, locations " that he hopes will help him save Yazidi girls and young women like this girl from the militants holding them captive. Shrem was a successful businessman ... when ISIS came and kidnapped more than 50 members of his family from Iraq's Sinjar province. Tens of thousands of Yazidis fled their homes ... while thousands of women and girls were abducted and sold into slavery. Desperate " and angered at what he saw as a lack of support from the international community " he began plotting to save them himself, recruiting cigarette smugglers used to sneaking illicit produce in and out of ISIS territory to help his efforts. So far, he says, his network has freed 240 Yazidis; it hasn't been easy, or cheap " he's almost broke, having spent his savings paying smuggling fees. A number of the smugglers have been captured and executed by ISIS while trying to track down Yazidi slaves. But Shrem insists the risks are worth it: "Whenever I save someone, it gives me strength and it gives me faith to keep going until I have been able to save them all." Once they manage to make contact ... it can take days or even weeks to get safely out of ISIS territory.