I tend to look for the good in bad people and the bad in good people, to make them human. 'Cause I don't think that people generally are that black and white. Maybe in movie-land they can be... but that isn't necessarily all there is.
The good thing about my part in 'Harry Potter' was that I was pretty well disguised. When I was walking down the street, there was no real recognition factor. Parents would sometimes call their children to come say hello to Mad-Eye, and the kids wouldn't know what they were looking at.