Search engine threat model
(Attacker-centric) organising thoughts and connections on two targets which are intertwined as many of the blackhat SEO techniques can also be used to fool users for more nefarious purposes: Security and privacy and threats to searchers (users of a search engine), hence search engines themselves are also listed as adversary; and search rank spam and fraud threats to search engines and their users.
Adversaries
Assets
Attack vectors
Attacks