Fears surrounding foreign influence and the proliferation of misinformation have prompted social media companies and governments globally to implement measures aimed at restricting or flagging non-local users' participation on large-scale platforms. However, these efforts may inadvertently compromise user privacy and impede freedom of expression. In this study, I examine a sudden policy shift on the Chinese social media platform Weibo, which sought to curb foreign influence by disclosing users' locations at the time of posting. As anticipated, I observe that this decrease in anonymity engenders a chilling effect, leading to diminished public discussion and political criticism of the Chinese government. Intriguingly, I also discover that unveiling users' IP addresses heightens the prominence of geographical identity politics in China, fostering animosity among localities and reducing cross-cutting dialogue on local political issues. I offer an analysis of the broader implications of reducing online user anonymity on political discourse and identity politics.