In a string of recent copyright cases, judges have increasingly adopted a technical approach to copyright law. Rather than evaluating contested technologies based on how the technologies are used, courts have focused their analysis on technical details of implementation. As a consequence, courts have constructed rules that limit technologies not in what they do, but how they do it. In this Article, I argue that courts should evaluate technologies based on functional considerations. I argue that this functional approach is constitutionally, statutorily, and practically preferable to a technical approach. Finally, I show that a functional approach would lead to decisions that are clearer, easier to understand, and better-reasoned.