What would you do?!?

Aaron and I went over to Huxley the other night to support the Dairy Queen (it was closed last summer and just reopened, so we want to help it stay open!!) We were sitting outside eating our ice cream when this station wagon drove by and we both were shocked to see a kid driving it. They pulled into the DQ parking lot and went through the drive-thru. As he pulled back out, it was VERY obvious that this kid was about 12 years old and had two other kids with him in the car, no adults. We were just stunned and we sat there and did absolutely nothing about it. I really wanted to do something, but what?? What would you have done??