Walt Mossberg, the veteran tech reporter and columnist, quit Elon Musk’s social media site over the mogul’s threat to sue the Anti-Defamation League — calling X a “cesspool” in a damning post on rival platform Threads. Mossberg — who covered technology for more than two decades at The Wall Street Journal before partnering with fellow journalist Kara Swisher on tech-centric ventures AllThingsD and Recode — blamed Musk for turning the rebranded Twitter site into a “cesspool” of “bigots and liars and pro-insurrectionists.” “I have deactivated my account on Twitter (X), which began in 2007,” Mossberg wrote on Threads, the “Twitter...