I've done quite a bit of work with public domain text. While more flexible copyright terms do have some advantages, it becomes a nightmare to work out whether o

I've done quite a bit of work with public domain text. While more flexible copyright terms do have some advantages, it becomes a nightmare to work out whether or not a given text is still in copyright, especially for the large majority of work that falls into obscurity. Copyright covers an enormous range of output. Keeping a central ledger that tracked the copyright status of hundreds of millions of items would be a massive undertaking.