BEIJING (CAIXIN GLOBAL) - China's months-long regulatory campaign targeting the tech sector is taking aim at a common practice that leading industry players deploy to foil rivals - blocking external links, which regulators consider anti-competitive.

For years, large Chinese internet companies from e-commerce behemoth Alibaba Group to social media giant Tencent Holdings have used various means to block their users from sharing links to posts and products on other companies' platforms. These techniques set up what are known as "walled gardens" to protect the creators' own digital ecosystems, stymie rivals' growth and prevent users from spending their cash elsewhere.