Several RVs were broken into several years ago in the "secure" facility where I keep mine by cutting thru the back 6' chain link fence. Got into my basement and stole a few things. Did not get inside. First I thought that was because I had latched the deadbolt. They had obviously pulled on my door handle. Then I saw a 5er on one side of me and a MH on the other side where they simply broke out the door windows and went in. They also had their deadbolts locked. Don't know why they didn't break mine. As mentioned above, the better it is locked, the more damage they will do getting in.