I agree 100% with Perfect Martini!!! This is also a peeve of mine. There was NOTHING at all copyright about that spreadsheet and I appreciated downloading it. I would never take the time to jump through all the new hoops to download it now so glad I got it when I did. Very well done.
I will also add that it doesn't make sense at all even from an ethical POV to try to make this so secretive.

Those who will steal the exercises could easily do so from logs or even from the book store. Those who would buy the book would do so even without the need to actually do the program. I purchased the book in order to follow along with all the logs and also because I thought the book had good information in it besides the exercises.