Sorry to read about the vandalism Zathras. I'm not a big fan of humans at all really.. as soon as you make something for yourself in life there is generally someone waiting to come along and take it away or spoil it !
We've been really lucky and haven't suffered any intrusion other than a couple of ramblers that lost the main footpath and they are very welcome, in my mind. Our wood is a mile from the nearest village and is on a main road. However, there is a poultry farm just opposite our entrance and their dogs and livestock make for quite a good burglar alarm - we often set them off when we arrive anyway. Most of all though, our wood is directly under the flight path of Gatwick airport and as such the road is patrolled regularly by police.. ( was recently contacted by them as they wanted to make sure I wasn't setting up any surface to air missiles in the wood !)
I had been thinking of installing a small shed in our wood but when I read things like this I'm more inclined to leave things just as they are and just carry tools back and forth instead.
Hope you don't get any more invaders!