By claiming that you would never, under any circumstances, steal (or commit any other sin), you show yourself to be a liar.
"If we say that we have no sin, we deceive ourselves, and the truth is not in us." (I John 1:8)
You, as a person with a sin nature just like everyone else on the planet, are just as capable of stealing as some guy who is already in gaol doing hard time for grand theft auto. You demonstrate that you don't have the truth in you by your denial of this, which is essentially you saying that you're a good enough person that "you'd never do that". This makes you self-righteous on top of being a liar.
When did I steal? I haven't actually. I just know well enough that anyone, myself included, could do so if put into the right (or wrong) circumstances. There's a reason even Solomon wrote,
"Two things have I required of thee; deny me them not before I die: Remove far from me vanity and lies: give me neither poverty nor riches; feed me with food convenient for me: Lest I be full, and deny thee, and say, Who is the LORD? or lest I be poor, and steal, and take the name of my God in vain." (Proverbs 30:7-9)
I think it'd certainly be possible for anyone, no matter who they are, to fall on hard times, get bitter about it, decide they don't want to do things God's way, and decide they want to try to score some easy money. It could happen to you, and I think you know deep down inside that what I'm saying is right, which is why you're getting so worked up about it.
Well, no wonder you have chosen to cast the first stone.