Other anthropologists have questioned whether barter is typically between "total" strangers, a form of barter known as "silent trade". Silent trade, also called silent barter, dumb barter ("dumb" here used in its old meaning of "mute"), or depot trade, is a method by which traders who cannot speak each other's language can trade without talking. However, Benjamin Orlove has shown that while barter occurs through "silent trade" (between strangers), it also occurs in commercial markets as well. "Because barter is a difficult way of conducting trade, it will occur only where there are strong institutional constraints on the use of money or where the barter symbolically denotes a special social relationship and is used in well-defined conditions. To sum up, multipurpose money in markets is like lubrication for machines - necessary for the most efficient function, but not necessary for the existence of the market itself."
Whether or not one agrees with such broad claims, it’s worth noting that monetary debt, a byproduct of currency, has regularly been used to by some groups to manipulate others. Thomas Jefferson, for instance, suggested that the government encourage Native Americans to purchase goods on credit so they’d fall into debt and be forced to sell their lands. Today, black neighborhoods are disproportionately plagued by debt-collection lawsuits. Even after taking income into account, debt collection suits are twice as common in black neighborhoods as in white ones. $34 million was seized from residents of St. Louis’ mostly black neighborhoods in suits filed between 2008 and 2012, much of which was seized from debtors’ paychecks. In Jennings, a St. Louis suburb, there was one suit for every four residents during those years.