We've never had anything stolen but we don't leave much out. Preventing the opportunity of theft is the key to not having stuff taken. We always put away lanterns, chairs, grills, etc. We chain up bicycles.
None of us can ever know for sure if anything is vulnerable to theft so...we've always been proactive. Another reason we continue this practice...a friend in the parking spot across from us at a state park we use annually in Ohio did have a bicycle stolen on a busy weekend. There were lots of families..one of the kids came along and took it. They found it at another site in the RV park.
All of this is especially true on busy weekends.