Is social media making America’s murder surge worse? 社交媒?是否?美?的??激增得更糟? One fall evening in 2020,Jarell Jackson and Shahjahan McCaskill were chatting in Jackson's Hyundai Sonata, still on a postvacation high, when 24 bullets ripped through the car.The two men,both 26, had been close friends since preschool.They'd just returned to West Philadelphia after a few days hang gliding,…