While China’s leaders have said little about their underlying intentions, analysts and investors float various theories. Some say regulators are simply reasserting their oversight power, or maybe those in power grew frustrated with the swagger of tech billionaires and wanted to teach them a lesson. Alibaba, Tencent and Ant had a combined market capitalization of nearly $2 trillion in 2020 — easily surpassing state-owned behemoths like Industrial & Commercial Bank of China Ltd. as the country’s most valuable companies. And it’s clear that the Communist Party had grown increasingly concerned about the growing clout of internet firms, which are mostly private entities over which it has little direct control of management. Much of that concern centers around their grip on the massive hoards of data that they hoover up from hundreds of millions, considered key to both driving the country’s economic and geopolitical goals and shoring up the Party’s power base. The Cyberspace Administration of China, the internet watchdog, cited data and national security as its prime reason for investigating Didi and now mandates a data security review for all companies seeking overseas listings. More broadly, Xi’s administration blames widening social disparities on the online boom, particularly in the pandemic era, and is moving to address discontent among the populace that could threaten its authority.