摘要：Videos have become a predominant part of users’ daily lives on the Web, especially with the emergence of video sharing services, such as YouTube. Part of the huge success of multimedia content in the Web is due to the change on the user perspective from content consumer to content creator. However, by allowing users to publicize their independently generated content, video sharing networks become susceptible to different types of pollution. As example, users can pollute the system spreading video messages containing undesirable content. Users can also associate metadata with videos in attempt to fool video search engines (i.e., popular tags, but unrelated to the content). Moreover, users can upload identical videos, generating duplicates of the same content on the system. Such pollution compromises not only the user satisfaction, but it also consumes system resources and can impact negatively aspects related to infrastructure. In this work we provide a general overview of pollution in video sharing systems. We define the different kinds of existent pollution, their negative impact to users and system and possible strategies to minimize the problem.
