臺北地院於西元2014年10月20日針對被告台哥大電信利用攜碼用戶集中式資料庫，開發名為M+ Messenger的通訊軟體一案作成判決，認定被告違法利用原告所使用手機電信業者別之個資，侵害原告之人格權。本案判決的作成之所以引起業界與法界注意，除了如同被告所擔憂之本案判決見解，恐將阻擾相關資訊科技的創新研發外，亦在於個人資料保護法於本案的適用不明。本文乃藉由本案的核心爭點：台哥大電信是否合法地就原告所使用之通信業者別的個資為原蒐集目的外的利用，說明新興資訊科技的發展，對於現行立基於「公平資訊實踐原則」所設計的資訊隱私保護制度所造成的衝擊；並以本案為例，說明個資法第20條第1項但書就目的外的個資再利用行為規定，應如何妥適地解釋適用。

The Taipei District Court handed down its decision on October 20, 2014 that Taiwan Mobile Co., Ltd. (hereinafter ＂Taiwan Mobile＂) has violated the Taiwan Personal Data Protection Act (hereinafter the ＂PDPA＂) by using M+ Messenger to illegally use personal data. The crux of the dispute lies in the question of whether Taiwan Mobile's communication application-M+ Messenger-infringed information privacy with its unique function to identify the mobile telephone service provider with which the M+ Messenger user's contact persons have engaged services. The Court decided that such function has constituted an illegal use of personal data and has infringed such contact person’s privacy right. This judgment aroused a lot of attention in the information privacy academia and the information technology industry with the concern that this decision is likely to impede technological advancement and the PDPA was not properly interpreted and applied. This article will examine whether Taiwan Mobile may legitimately use personal data for the purpose which is different from the one when the same data was collected. This is a reallife example to illustrate how the emerging technologies have posed challenges to the fair information practice principles and how the Paragraph 1, Article 20 of the PDPA shall be correctly interpreted and applied in the context of this M+ Messenger issue.