The three biggest private employers in North America are Walmart, Amazon, and a security firm you’ve maybe never heard of: Allied Universal. Time’s Alana Semuels explains the rise of poorly trained and poorly paid private security guards across America.This episode was produced by Miles Bryan, edited by Matt Collette, fact-checked by Laura Bullard, engineered by Patrick Boyd and Michael Raphael, and hosted by Noel King.Transcript at vox.com/todayexplainedSupport Today, Explained by making a financial contribution to Vox! bit.ly/givepodcastsLearn more about your ad choices. Visit podcastchoices.com/adchoices