Someone jacked my gas!

So I went to a late dinner tonight with Liza and while we were in the restaurant I think someone siphoned the gas right out of my car. Let me back up just a little. I have the kind of display on my dashboard that tells you how many miles you have left to drive your car before you are out of gas. I usually have my display showing so I know just how far I can coast on fumes before I have to fill up. After running my errands this morning, I distinctly remember looking at my mileage left and it said 132 miles. OK, good-- I have a couple more days before I have to fill up again. The only places I drove after that were to pick the kids up from Mother's Day Out, go to the grocery store and meet Liza at the restaurant. Maybe a total of 32 miles--our town is not that big. So now I would be down to 100 miles right? That would be about 1/3 of a tank. While at the restaurant, I parked in front and while the side of the car with the gas tank was not well lit, my car was in full view of anyone that walked in and out. When I got in my car to go home and turned it on, I noticed that the gas light was on but didn't think anything of it because my car always uses gas quicker than I think. But then it hit me how much gas I KNOW I had since I had been looking at the mileage display all day. I don't know much about cars but I'm pretty sure that no gas is burned while the car is off. My gas light was not on when I drove to the restaurant. The only conclusion I can come to on how I went from 1/3 of a tank to nothing is that someone siphoned my gas while I was in the restaurant. I don't have a gas leak, I know how much gas I had left and it wasn't on Empty!! Am I being paranoid? I called Liza to see if she still had gas and she indeed still had her half a tank. I had to fill up on the way home because I didn't even have enough to make it home. I know my car is a gas guzzler but it doesn't use it that fast! Luckily it wasn't full or I would have been really ticked that someone made off with my hard earned gas. So whoever took my gas, shame on you. I hope your car runs out of gas in the middle of nowhere at night and you have to hike down a scary road by yourself to find a gas station only to find that it's closed.