Technical issues are not the only ones preventing large scale introduction of online streaming video services. Unlike generic web browsing applications, streaming video imposes greater demands on network resources. Caching of content through the use of distributed servers has been proposed as a solution to reduce resource requirements and improve scalability. Video caching presents a unique challenge to copyright protection schemes, particularly if we consider provision of functionality such as indexed and high-speed playback modes. This paper discusses the issues involved in implementing copyright protection for cached streaming video, concluding with a set of requirements for any proposed scheme.