They ran checks on employees' immigration status and arrested 21 people.

他们对员工进行了移民背景调查，逮捕21人。

Work arrangements that increasingly carve workers out of employee status, not only lessen employer's responsibilities, but make it all the more challenging to hold them accountable for labor violations, as well as unsafe working conditions.

越来越多地使工人脱离雇员身份的工作安排，不仅减轻了雇主的责任，而且使追究他们对违反劳动法以及不安全的工作条件的责任变得更具挑战性。