Harry Potter and the Half-Blood Prince
"I don't think you should be an Auror, Harry," said Luna unexpectedly. Everybody looked at her. "The Aurors are part of the Rotfang Conspiracy, I thought everyone knew that. They're working to bring down the Ministry of Magic from within using a combination of Dark Magic and gum disease."
"Well, of course, to you it will matter enormously," said Scrimgeour with a laugh. "But to the Wizarding community at large…it's all perception, isn't it? It's what people believe that's important." (16.189)
"If you were to be seen popping in and out of the Ministry from time to time, for instance, that would give the right impression. And of course, while you were there, you would have ample opportunity to speak to Gawain Robards, my successor as Head of the Auror office. Dolores Umbridge has told me that you cherish an ambition to become an Auror. Well, that could be arranged very easily…" (16.194).