We never had anything stolen from our TT, but it was broken into twice when we first moved to GA. The first time it happened, we figured they were looking for valuables, which we didn't have. I had only locked the door lock and they easily broke in.
After that incident, I locked the deadbolt. The second time they tried they couldn't get in and they were not happy. They couldn't get past the deadbolt. They broke the glass trying to reach in and unlock it. They couldn't so they tried tearing the door open from the window, but didn't have much luck. They must have been pissed they couldn't get in, because they cut the plastic tether that holds the fresh water fill cap in place while filling and the cut the coupler lock.
I inspected the only other TT on the lot and noticed their lock had also been broken and their tongue lock (the kind with a hitch ball on it) had been broken. The police figured it was probably someone looking for a place to spend the night(s).
We removed the TT that night and found another storage lot. It's been there for 6 years without incident. I replaced the door myself for the cost of the door and freight, about $390. Unfortunately, the police didn't seem to care and nothing ever came of it.
-Michael