I really like the recently published Ethical Principles of the W3C. They sum up a lot of what the Web should be:
"The web should empower an equitable, informed and interconnected society. It has been, and should continue to be, designed to enable communication and knowledge-sharing for everyone. In order for the web to continue to be beneficial to society, we need to consider the ethical implications of our work when we build web technologies, applications, and sites."
Ethical Web Principles
The web should be a platform that helps people and provides a positive social benefit. As we continue to evolve the web platform, we must therefore consider the consequences of our work. The following document sets out ethical principles that will drive W3C's continuing work in this direction.