We may not know (or even want to know) the details. But we know on an intuitive level that if we can buy stuff for a really small amount of money then someone on the other side of that supply chain is being exploited. Well, it’s worse than you think. Ian Urbina in The New Yorker: Inside North Korea’s Forced-Labor Program. “Workers sent from the country to Chinese factories describe enduring beatings and sexual abuse, having their wages taken by the state, and being told that if they try to escape they will be ‘killed without a trace.'” And you’re not just buying a new device. You’re buying weapons for Kim Jong Un. “The program is run by various entities in the North Korean government, including a secretive agency called Room 39, which oversees activities such as money laundering and cyberattacks, and which funds the country’s nuclear- and ballistic-missile programs. (The agency is so named, according to some defectors, because it is based in the ninth room on the third floor of the Korean Workers’ Party headquarters.) Such labor transfers are not new. In 2012, North Korea sent some forty thousand workers to China. A portion of their salaries was taken by the state, providing a vital source of foreign currency for Party officials: at the time, a Seoul-based think tank estimated that the country made as much as $2.3 billion a year through the program. Since then, North Koreans have been sent to Russia, Poland, Qatar, Uruguay, and Mali.”