Do you honestly think the phantom thieves are Just?
Oh, is that you traverse the hearts of strangers, to help <i>them</i>? Because i'm sure bettering the lives of those you mark as targets <i>really</i> crossed your mind.
Tell me, why is it you chose to become a Phantom Thief? Was it some lofty ideal of bettering society, as you say, or did you merely seek to better your own life? Maybe even make some friends along the way, go down in fame and all that.
In the end, you're not all that different myself. I mean, defending one's personal interests should come first, after all. Wouldn't you agree?