在網路世界中，人們以匿名表達意見遠比現實生活中更為容易，這件事已劇烈地改變了匿名言論的量與質。從好的面向看，匿名帶來自主，讓異議者可以透過網路匿名，表達可能永遠都不敢在眾人面前說出來的真正想法，讓觀念市場變得多元豐富；另一方面，匿名提高了追究責任的困難。相較於現實世界的言論，損害他人或構成犯罪的惡質網路匿名言論，將造成影響更深遠且永久的傷害。 　　目前，關於網路匿名言論的管制方式，世界各國政府都是仰賴「事後追懲模式」和「實名認證模式」的其中一種。前者是網路使用者原則上可以匿名地發表言論，但如果發表不當言論並造成傷害，受害者或國家可以揭露其身份以對其展開司法追訴；後者是網路使用者在張貼言論前，必須先向國家機關指定的網路業者交出個人真實身份資料以進行驗證後，才能匿名發言，或甚至完全禁止以匿名方式發言，讓網路使用者感受到被眾人監督的壓力，不敢發表不當內容。 　　本文主張，網路匿名言論是受到憲法所保障的權利，而「事後追懲模式」相較於「實名認證模式」，較能調和不同權利間的衝突。不過，儘管我國政府採取此模式，卻在設計民刑事訴訟制度時，漏未導入匿名言論權利的思考，導致網路匿名表意者一經策略性訴訟攻擊，真實身份就會立即暴露，使得匿名表意自由不過徒有虛幻表象。因此，本文建議，為落實對匿名言論自由的保護，立法者宜參考美國法，修改部分訴訟法來處理此問題。 / On the internet, people can express themselves anonymously far easier than in the physical world. This fact has dramatically changed both the quantities and qualities of anonymous speech. On the bright side, anonymity brings more autonomy. Dissenters can express their real opinions, which they might never have the courage to speak out in public. It, in turn will promote the diversity and integrity of the marketplace of ideas. Yet, anonymity also makes it more difficult to hold the speakers accountable. In addition, compared to speech in the real physical world, malicious online anonymous speech will cause more serious permanent harms. 　　Today, governments around the world are either relying on the “Ex Post Compensation and Punishment” approach or the “Real-Name Verification System” to regulate online anonymous speech. Under the former approach, internet users can express their opinions anonymously, but if the content of their speech is malicious and causes damages to other people, the victim can seek disclosure of the speaker’s identity in order to take legal actions against the speaker. In contrast, under the latter system, internet users have to provide their personal information (real identities) to the ISPs or ICPs appointed by governments and complete the verification process before they can post their words. Some real name systems go even further by banning anonymous speech completely. By making users feel like they are being supervised by the public, the real name system wishes to deter indecent contents 　　This thesis argues that online anonymous speech is protected by the Constitution, and the ‘Ex Post Compensation and Punishment’ is a preferred approach because it can better balance the conflicting rights. In Taiwan, although the government has chosen the ‘Ex Post Compensation and Punishment’ approach, current civil/criminal procedural laws and practices afford little protection to online anonymous speakers. The plaintiff, who is allegedly harmed by the anonymous speech, can easily bring a “Strategic Lawsuit,” with the sole purpose of obtaining the identity of the online anonymous speaker. Consequently, this thesis suggests that, in order to better protect the freedom of anonymous speech, the legislators of Taiwan should refer to U.S. laws and practices and revise several provisions of Taiwan’s Code of Civil Procedure and Code of Criminal Procedure.