Reading Between the Lines: Lessons from the SDMI Challenge: When a team led by Princeton Professor Edward Felten accepted a public challenge by the Secure Digital Music Initiative (SDMI) to break new security systems, they did not give up their First Amendment right to teach others what they learned. Yet they have been threatened by SDMI and the Recording Industry Association of America (RIAA) to keep silent or face litigation under the Digital Millennium Copyright Act (DMCA). Professor Felten has a career teaching people about security, yet the recording industry has censored him for finding weaknesses in their security. USENIX regularly publishes scientific papers that describe the weaknesses of technologies, but they are chilled by RIAA litigation threats.