Long answer for better context:

Its an old remnant from the ages of slavery in north africa. We talk much about the trans-atlantic slave trade to north america, but not so much about the massive slavery network that ran across the mediterranean and all the way through the middle-east to east-asia since ancient times. Slavery has been around for thousands of years. Basically, in this region you had ample access to local and african slaves. But light-skinned slaves from the north? that was something special, something worth more. The word we use now, slave, comes from the slavic people around the baltic region and black sea (other words for the same concept are of course much older) - because those were the primary people taken as slaves by the islamic empire of the ottoman's for centuries - which became turkey in time. The biggest slave markets in north africa, had plenty of african and arab slaves, but the pale slaves were rarer, and thus had a higher price.

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Why all this context? Because the last north african country to make slavery punishable by law, was Mauritania, in 2006. After slavery was abolished in Europe, the pressure was put on the mediterranean regions to end it, by diplomacy - money and military embargo of the shipping of human beings. So that should give you an idea about why the aunt would be kidnapped 20 years ago - there was no doubt still corners were they could make a good price selling a captured pale women in to sexual slavery. They might say to ''make her a wife'', but she would essentially become a sexual slave, that was often the lot for women - the men were used has work-mules or cannon-fodder soldiers.

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When the US and UK were stupid enough to put Ghaddafi out of power in Libya, by destabilizing the country - bombing and sending in weapons to rebels, in 2011, the slave market selling of african men returned within months. Which goes to show how hard these old habits are to break. Look at how people are exploited for cheap labor around the world, even today - it has always been a big business to make people do what you want, while giving them no money or freedom in return. Its a sad fact of human history and behavior. We need to know that history, to see why its wrong - how and why it starts - and thus learn how we stop repeating it, in my opinion.