Pickoff move to 3rd

Question
I used to do this in Babe Ruth league, but I still don't know if it is legal.  Guy on 3rd base, pitcher is in the stretch.  He then attempts a pickoff of the runner at 3rd in much the same manner as a lefty tries to pick off a runner at 1st.  I used to pick off guys left and right doing this.  Nobody ever called a balk, and I can only recall a couple of times when I guy was not picked off when I did this.
Nevertheless, I was the only one I ever saw do this (other than the fake throw to 3rd, throw to 1st pickoff move).  So, is this legal?  And why don't we see more of it?
Thanks.

Answer
Mark,

This is perfectly legal as long as the first move and the step is toward third base.

A couple reasons you don't see this that much:

1)  Runners typically don't take a big lead off of third.  There just isn't that much threat of a steal of home.
2)  It is a riskier play then the throw to first.  If the ball is thrown away, it is a run.  Typically if a ball to 1st is thrown away, it is just a base or maybe two.

Just my two cents!

Brian