We’ve got a van that we leave parked near our house by the John Stanford school. A couple times over the past few months, I went to drive it, and was surprised to find the tank on empty, when I thought I had filled in recently. I mentioned it to my wife, who pointed me towards a recent post to the Green Lake Moms mailing list from someone who suspected that their gas tank was being siphoned.
So, when I filled it and parked it this past week, I carefully noted the tank level (half). Sure enough, went I went to drive it several days later, the tank was completely empty, with just enough left to get me to the filling station.
Perhaps its our proximity to the I-5 bridge / University District, but if you’ve suspected the same, you’re not crazy.