Not sure you can call it censorship if it's the author of the book who doesn't want you to access it for free. I know there are a few levels of indirection here, but with a few notable exceptions authors are normally against their books being pirated.
I personally sure want Anna's Archive staying up, but comparing it to nazis burning books is a bit too much IMO
This isn't banning books, it's akin to banning a book store. If a book store chain isn't paying their taxes and gets shut down, the books have not been banned or censored.