On July 6, 2011, some of the world’s largest entertainment companies, including Disney, Paramount, Warner Brothers, and Universal, as well as the MPAA and RIAA, entered into a historic agreement with the most prominent internet service providers (ISPs), including AT&T, Verizon, and Time Warner. Their agreement created the Copyright Alert System. Under the system, copyright owners will be able to inform ISPs of the IP addresses of suspected infringers, and ISPs will then act on their own to impose a graduating series of sanctions on their subscribers, up to and including slowing connection speeds or suspending Internet service. ISPs are expected to begin rolling out Copyright Alert in late 2012. This Note provides the first in-depth scholarly treatment of Copyright Alert. The discussion begins with a survey of the circumstances that led to Copyright Alert: clunky copyright laws unsuited to address infringement by individual Internet users coupled with a cultural acceptance or even valorization of piracy. Faced with legal and cultural hurdles to enforcement, copyright owners and ISPs have become vigilantes for their own cause, turning to private enforcement to accomplish what the copyright law could not. The Note moves on to address the strengths and weaknesses of the Copyright Alert system, leading to the conclusion that although a graduated response system can create gains in efficiency, privacy, and fairness over current copyright enforcement, regulatory oversight could help alleviate competency, legitimacy, and implementation problems that will otherwise hinder the sustainability and effectiveness of Copyright Alert.