The villains consider themselves heroes?

In most movies, villains are portrayed as truly evil. There are only a few films that explore the underlying motives of the antagonist's behavior. The same is true for reality. While there are scary psychopaths who do evil things without a valid reason, it's also possible that there are people who do evil because they believe it's the right thing to do. This is a suggestive question: are there any such evil people who really believe they are heroes?