We're not using the same definition of community. A community that shares a public library is a community that shares a very broad range of common customs, tra

We're not using the same definition of community. A community that shares a public library is a community that shares a very broad range of common customs, traditions, values, and interests. They are literal neighbors. They have a shared interest in the success of the community along multiple economic, social, and cultural dimensions. "Knowledge for the common good" is a value, but pursuit of that value conflicts with other things the community also values. Resolution of all those conflicts provides natural checks and balances. The only common interest of the "file sharing community" is sharing files, and any political or technical issues that happen to be directly related to sharing files. The virtual community can grow and expand infinitely based on only that one dimension. There are no natural checks and balances the way there would be for a real community. Instead of resolving conflicts, anyone who doesn't share that one primary value is not part of the community.