What is "bad old man, very bad"? Why do people say "bad old man, very bad" on the Internet?

Network buzzwords. The whole sentence is like this: I believe you, a ghost, a bad old man!

"I believe you are a ghost. You are a bad old man." This sentence does not have any derogatory color of swearing, it is purely an expression of inner dissatisfaction. When people are deceived and fooled, and there is a small angry flame burning in their hearts, they will reply with a sentence "I believe you are a ghost" or "you are a bad old man" to express their inner indignation.