Book excerpt: This paper examines the impact of the technological measures that copyright holders employ to lock their works and discusses why users are disadvantaged. It compares the anticircumvention rules in the Digital Millenium Copyright Act in the US and the Copyright, Patents and Designs Act in the UK; the latest exemptions to circumventing activities released by the US Library of Congress are included. It reviews the evolution of Chinese anti-circumvention rules, starting with a well-known case preceding the promulgation of the anti-circumvention rules, then it examines the anti-circumvention provisions in the Copyright Act 1990, the Software Regulation 2001 and the ISP Interpretation 2004. It also critically analyzes the latest Network Regulation 2006 by comparing it with the DMCA and the CDPA. The paper suggests that the Chinese anticircumvention rules need to be constructed with more legal certainties. Recommendations are also made for additional redrafting to make China's anti-circumvention rules more adaptive to a digital environment.