The key to successful poisoning attacks is to introduce brand new information that doesn't directly contradict other training data. It's much easier to convince the LLMs that you're the king of a fictional Mapupu kingdom than the president of the United States.

So this means that for bad actors it's more efficient to manufacture brand new fake stories instead of trying to distort the real ones. Don't produce fake articles absolving yourself of a crime, instead produce fake articles accusing your opponent of 100 different things. Then people will fact-check the accusations using LLMs, and since all the sources mentioning those accusations are controlled by you, the LLMs will confirm them.