I realized it might not be a common name for the concept after using it here so here's the post:

When your ship docked in Alexandria, as a requirement of using the port, every written word you brought with you would be confiscated, copied and added to the Library, and returned to you before you left.

A really common way to build libraries among groups of friends / etc now that ebooks are a thing, is to have everyone dump their ebooks anonymously into a shared drive.

sorry but this hackerspace now works on library of alexandrea rules: you give us your web history and a script pulls down and anonymizes all of the erotica before returning it to you otherwise untouched