"Basically, LLMs often return content that reads similar to the query that users ask it, so brands doing AI-engine optimization can study what people are asking AI and can create content that closely mirrors those queries on Reddit."

https://www.404media.co/it-is-trivially-easy-to-use-reddit-to-manipulate-ai-search-research-suggests/

It Is Trivially Easy to Use Reddit to Manipulate AI Search, Research Suggests

"We show that a tiny snippet—just 13 words—of retrieved text on a UGC website like Reddit, Wikipedia, Quora, or Facebook can change AI agents to output spam / scam content pretty consistently."

404 Media