I wonder how many military vehicles have been stolen that are in private civilian hands. I could see like a M48 sitting in someones storage shed. There was a case awhile back where some guys stole over a hundred military vehicles from Fort McCoy. It seems likely to me this could happen easily when you have stuff that is no longer being used. The guy at the gate most likely wouldn't think much of it.
http://www.lasvegassun.com/news/1996...t-ring-broken/