I had no siblings, so I had to wait until I had kids to steal from theirs.

Unless you're going to count the couple times I mugged little kids for their goody bag when I was about 15.

Sure, as a kid we all did this to an extent.

No... they use to take mine all the time. I didn't care though. I use to have fun trick or treating. I've never been too into candy, but, nobody better lay a finger on my Butter Finger.

I never had to; we always traded.

Nah, we were always trading. Those were some fun negotiations.
"I'll give you two tootsie rolls for a Snickers."
"Are you high?"
"But they're the big ones!"
"...and you have fifty of them. No deal."

By the time my sister and I were old enough to Trick or Treat I had learned my lesson. Prior to that, I was once caught sneaking chocolate candies out of her little heart shaped Valentine candy box that our father gave us. I figured, heck she's little she'll never notice. That's when I found out just how sharp she was and how nasty guilt could be. I resigned from stealing candy then and there.

Depends...it's not so bad if you're close in age, but even I never stole from the youngest ones, who were 11 and 12 years younger. I mean, I've done a lot of things I'm not proud of, but never quite stooped to stealing candy from babies.