Eliezer Yudkowsky
"I'm certainly becoming a bit frustrated with... whatever's going wrong in people's heads."
"Yes," said that icy voice. "I find it frustrating as well."
"Is there any way to get people not to do that?" said Harry.
"There is indeed a certain useful spell which solves the problem."
Harry looked up hopefully at that, and saw a cold, cold smile on the Professor's face.
Then Harry got it. "I mean, besides Avada Kedavra."