One of the most insidious problems in the current AI ecosystem is “Hallucinated Authority.” This phenomenon occurs when an AI model trusts a domain because of its historical reputation in the training set, even though the domain has since expired, been auctioned, and is now hosting spam or disinformation.

For the MCP-SEO professional, avoiding citations from these “Zombie Domains” is critical. Linking to them damages your own “Co-Citation Trust,” effectively poisoning your site’s reputation in the eyes of the model.

The Mechanism of Zombie Knowledge

LLMs (Large Language Models) have a training cutoff. A model trained on Common Crawl 2023 “remembers” example-health-org.com as a reputable medical non-profit. It has high weights for trust and accuracy associated with that domain string.

In 2024, the non-profit dissolves. The domain expires. A spammer buys it for $10 and fills it with AI-generated gambling content or affiliate links.

In 2025, an agent using RAG (Retrieval-Augmented Generation) searches for medical advice. The spammer might use “cloaking” to serve some legacy medical content to the bot. The agent retrieves this content. Because the domain example-health-org.com is highly rated in its parametric memory, the agent trusts the spam. It “hallucinates” that the domain is still authoritative.

Vector Drift Analysis: The Defense

How do we detect this? We use a technique called Vector Drift Analysis.

We track the semantic centroid of a domain over time using embedding models (like OpenAI’s text-embedding-3-small).

  1. Baseline Vector (V_t0): In 2023, the domain’s content clustered around vectors for “Medicine,” “Health,” “Public Policy,” “Research.”
  2. Current Vector (V_t1): In 2026, the content clusters around “Casino,” “Betting,” “Bonus,” “Slots.”

We calculate the Cosine Distance between V_t0 and V_t1. If the distance exceeds a certain threshold (e.g., > 0.4), it indicates a “Topic Shift.”

This “Drift Score” is a red flag. Search engines and advanced agents are beginning to implement this logic to “reset” the authority of domains that drift too far from their historical topic clusters.

To protect your site, you should deploy a simple auditing agent.

  • Step 1: Crawl all your outbound links.
  • Step 2: Fetch the current content of the target page.
  • Step 3: Classify the content topic.
  • Step 4: Compare with the anchor text context.

If you link to a site with the anchor text “latest cancer research,” but the target page is classified as “cryptocurrency,” you have a drift event. Remove the link immediately. Semantic consistency is the new broken link check.