I used gemini to look up a relative with a connection to a famous event. The relative himself is obscure, but I have some of his writings and I've heard his story from other relatives. Gemini fabricated a completely false narrative about my relative that was much more exciting than what actually happened. I spent a bunch of time looking at the sources that Gemini supplied trying to verify things and although the sources were real, the story Gemini came up with was completely made up.
Yup. I've had Gemini create fake citations to papers. I've also had it hallucinate the contents of paywalled papers, so I know I can't trust anything it writes, though I am getting better at using it recursively to verify things.
I am certain I read article that was posted on YN a month or so ago about some researchers that were caught using false citations in their research.
If I remember correctly, some group used an AI tool to sniff for AI citations in other's works. What I remember most was how abhorrent some of the sources that the AI sniffer caught. One of the citation's authors was literally cited as "FirstName LastName" -- didn't even sub in a fake name lol.
Edit: I found the OP:
https://news.ycombinator.com/item?id=46720395