[ethbro]

That's the difference between people designing a system against a malicious adversary and a user.

Nowadays, if it involves money, for godsakes please assume the former.

[chaosfox]

the system is still bad even without a malicious party, as said in the article, if the user go back to page 1 after reading the book the system will count the book as unread and the author will not get paid.

[DanHulton]

Pretty sure that's not true. They sync "furthest page read" not "last page read".