Don't worry Gardenia, you didn't upset anyone with your statements and I think we can relate to them or understand them to a large extent.
I believe (but could be mistaken) that anony has based his decision on what would be most practical and least hypocritical way of doing things considering the valid legal implications of copyright.
As for uploading scans, I was not justifying it by saying the people who bought it reserve the right to do whatever with it. I'm saying they own the artwork now. There's really nothing that's going to stop them from uploading.
That's actually not entirely correct, if you buy an artbook, it does not give you any ownership of the artworks portrayed therein and you are legally not allowed to reproduce it or upload/distribute its contents to the Internet (or other media).
In legal terms of copyright, scanning and uploading an artbook you bought and paid for is as much a copyright infringement as resposting an image from an artist's website that has a disclaimer not to repost his/her images. Legally and logically they are the same infraction.
When you purchase an artbook (or say a CD, DVD), you do not aquire any ownership or copyright rights over the contents, nor do you have any legal rights to copy those contents, you only have the right to the contents for personal use (which excludes reproduction).