In some interpretation of copyright law, it’s considered a “transfer” rather than a “copy” if you destroy the physical original. (Ignore all subsequent copying of the digital version.)

Actually old and rare books are probably public domain, so that’s not an argument.

Also, most of the books they scan/destroy are low quality trashy novels that won’t even sell at thrift stores. But as they are written by humans it is still useful for training models.

It’s not the first time I’ve seen someone (mis)using the word “torrent” when asking about piracy in the 90s.

CMR is faster, but SMR is cheaper. (Very simplified.)