Comment by dragonwriter

> While I'm sympathetic to the basic emotion, it's hard to see what it would mean within a legal framework.

One way of doing it would be shift copyright to a short free-and-no-required-registration period, with longer protection requiring registration, declaration of stated value, and payment of an annual ad valorem tax on that value; during the extended period, any individual or group could buy the work into the public domain by payment of the declared value, which would be forwarded to the copyright owner.