This is not a patent on the linked list. It's a patent on a modification of the linked list that provides a secondary (and possibly tertiary, etc.) traversal path. The patent should not have been granted, and should be deemed invalid if it ever goes to court, but it is not a patent on just the linked list. The anti-patent crowd makes themselves look bad by trotting out examples like this and being deceptive about the…
Sorry, but Linked List is class of similar things -- Single-, Double-, Multiple-linkings are all part of the Linked List genre. Just because you associate Linked List strongest with the singly-linked list does not mean that other forms of the same thing, all of which qualify as linked list, can't be called it as well. You are just being disingenuous -- stop it, that is not cool.
The term "linked list" refers to singly and doubly-linked lists, which may be circular and/or sorted. This is from Intro to Algorithms (2nd ed). It's not just my personal association here.