If I notice someone is using the auto fold button, I will raise more times against him/her. I use it myself very seldom, usually not once per tourney, but there are times when I do once in a row. never more.
I watched my brother play and I asked him why he did it. He said I already decided. I then said, what if it is folded to you and you are in a heads up situation? He always wondered how come a lot more players raise his blinds than mine. I told him, most times you are on auto fold and I am sure if they were paying attention, they know. And like me will raise you, I told him that is one thing I look for.