[nwatson]

A "real-world" library's goal of knowledge-sharing is balanced with the need of the content-provider to make some money to support distribution and authoring of books. The public pays taxes to fund libraries so that people who can't afford to buy (or choose to not buy) particular books can still access them. There's a natural brake on distribution in that each copy can be checked out to at most one library patron at a time.

The most direct analogy carried over to the electronic space is e-book lending systems with built-in DRM. These systems usually keep the N-number-of-copies-available-for-loan restriction in place. Unlimited file-sharing does not at all resemble the balance between the-good-of-public-knowledge vs the-right-and-need-for-publishers-and-authors-to-make-money that a physical library model provides.

[jbob2000]

I would argue that the "need for publishers and authors to make money" is where the issue lies, not in the means of knowledge transfer (libraries vs. file sharing).

Just like how governments subsidize libraries, so too should they subsidize file sharing.