Wikipedia is the online encyclopedia that "anyone can edit." Unless you want to edit the entries on Albert Einstein, human rights in China or Christina Aguilera. Wikipedia's come-one, come-all invitation to write and edit articles, and the surprisingly successful results, have captured the public imagination. But it is not the experiment in freewheeling collective creativity it might seem to be, because maintaining so much openness inevitably involves some tradeoffs. At its core, Wikipedia is not just a reference work but also an online community that has built itself a bureaucracy of sorts...