Nearly twenty years ago, Congress passed the Digital Millennium Copyright Act (DMCA), establishing copyright rules specifically tailored for the online world. Although the DMCA has succeeded admirably in fostering the growth of the internet, some copyright industry representatives have advocated for a rewrite of the law to force OSPs to implement content filtering technologies as a prerequisite to obtain the protections of the DMCA's safe harbors. In evaluating these calls for mandatory filtering, policymakers should consider how such filtering tools actually work in practice and the impact they are likely to have on infringement, startup activity, and creative production.
This paper, co-authored by Engine's Evan Engstrom and Princeton University's Nick Feamster, examines the functionality and inherent limitations of the most common filtering technologies to demonstrate why a mandatory filtering regime would pose grave dangers to the viability of the internet ecosystem in exchange for a minimal effects on online infringement.