I absolutely agree that you must be careful when selling on Craigslist or anywhere else on the Internet. It is no different than the days before computers though when you sold via the local newspaper classifieds. Well, except for the fact that you are reaching people who may be further away.
I can remember when I was a kid that my dad had a car listed in the local newspaper. A man came to look at it, got in it and started it up then just drove away and didn't come back. The police found him the next day though. He had driven the car to a liquor store in a nearby town. Bought a bottle of whiskey and then parked in a wooded and drank till he passed out.
Guess he just needed a ride to the store.