At the beginning of this year, I was sad to learn of the passing of Peter Kollock. He was one of the first to carefully think about cooperation and online communities. I've been citing his 1996 paper "The Economies of Online Cooperation: Gifts and Public Goods in Cyberspace" for a long time now.
Unfortunately, while checking Web references, I discovered the above link to his paper no longer works (i.e., 404). This is the link that appears on his Wikipedia page and dozens of online bibliographies. It appears UCLA yanked his whole web space. The lack of institutional commitment to preserving work and providing stable URIs has always been a great irritation (e.g., see my entry on digital posterity about the links in my dissertation that were soon broken); at the W3C we would frequently talk about this frustration and how to best maintain our own commitment to preservation. And it's not only in death that our work soon disappears. After my time at the Berkman Center, subsequent to a Web site reorganization, I noted all the links to my work there were broken. They were able, and kind enough, to restore the HTML files though my biographical page looks screwy because of broken CSS and relative links -- so I don't even link to that anymore.
In the case of this particular paper by Kollock, it was fortunately published in a book, and I found a PDF version as well -- though I preferred the HTML.
Kollock, P. (1999a). The economies of online cooperation: Gifts and public goods in cyberspace. In Smith, M. and Kollock, P., editors, Communities in Cyberspace. Routledge Press, London. URL http://dlc.dlib.indiana.edu/archive/00002998/