>(The quote is from the parent's comment, not the one I directly replied to but my reply fits here better.) This is not permissible under copyright law, and never has been. That would be creating a new copy, which is exactly what copyright law was created to prevent.

My understanding is that this is entirely legal as long as you don't sell the copy. Borrowing/giving it away would likely be illegal but not worth prosecuting. But a copy solely as a personal backup is allowed. We do that with data all the time.