PT Journal AU Kornelius, W TI Prior filtering obligations after Case C-401/19: balancing the content moderation triangle A comparative analysis of the legal implications of Case C-401/19 for filtering obligations ex ante and the freedom of expression in Europe SO JIPITEC PY 2023 BP 123 EP None VL 14 IS 1 DE content moderation; freedom of expression; general monitoring obligation; illegal content; online platforms AB On 26 April 2022, the CJEU finally delivered its judgment (Case C-401/19 Poland v. Parliament and Council) on the compatibility of Article 17 DSM-directive with the freedom of expression (Article 11 Charter). Article 17 DSM-directive introduces an obligation for online content-sharing platforms to proactively prevent uploads of copyright infringing material. This de facto requires them to resort to automatic filtering technologies with a potential of over-blocking. The CJEU concluded that such prior filtering restricts an important means of disseminating online content and therefore constitutes a limitation of Article 11 of the EU Charter. The CJEU nevertheless upheld Article 17, finding a justification for this limitation. Several scholars have suggested that the CJEU’s conclusions have implications outside the copyright realm on obligations for platforms to detect illegal content. Although this linkage is suggested, it has up to now not been looked into exhaustively. This article aims to answer the question what the legal implications of Case C-401/19 are for the regime of de facto obligations on online content-sharing platforms under EU law to act against illegal content ex ante more generally. It distils other de facto obligations on online content-sharing platforms to carry out a prior review of content. These obligations are all governed by the prohibition of general monitoring obligations (e.g. Article 8 DSA). The CJEU treats this prohibition as a safeguard to the freedom of expression. Consequently, online content-sharing platforms should only block content that is clearly illegal. This article shows that the fundamental importance of the freedom of expression and information of the users of the internet needs to play a key role in designing obligations to act against illegal content both inside and outside the area of copyright law. ER