Copyright started with a dispute between Scottish and English
publishers, and the first copyright law, 1709's Statute of
Anne, conferred the exclusive right to publish new editions of a
book on the copyright holder. It was a fair competition statute,
and it was silent on the rights that the copyright holder had in
respect of his customers: the readers. Publishers got a legal
tool to fight their competitors, a legal tool that made a distinction
between the corpus — a physical book — and the spirit —
the novel writ on its pages. But this legal nicety was not
"customer-facing." As far as a reader was concerned, once she
bought a book, she got the same rights to it as she got to any
other physical object, like a potato or a shovel. Of course, the
reader couldn't print a new edition, but this had as much to do
with the realities of technology as it did with the law. Printing
presses were rare and expensive: telling a 17th-century reader
that he wasn't allowed to print a new edition of a book you sold
him was about as meaningful as telling him he wasn't allowed
to have it laser-etched on the surface of the moon. Publishing
books wasn't something readers did.

the realpolitik of unauthorized use is that users are not required to secure permission for uses that the rights holder will never discover