In the book the usable members are firstly protected (P191) then on the following page they are public. They are also public in the Loki source. Protected is the access specifier that is required. The Loki source code needs fixing. I'll add something to the books errata list.
Thanks for alerting us to the accessibility of the OwnershipPolicy classes. I will take a look into this.
I fixed this in revisions 1028 and 1029. All the SmartPtr policies used protected functions by default now.