LandLord Over Reaching?

Your land lord has definitely over stepped his bounds. I don't know the laws in your state, but I have been a land lord before. First, you have a right to your privacy and when he went into your home or building he violated that right. Second, when he took property of yours and destroyed your property that's theft and vandalism. I hope you get a cheap rate on your rent, because you just paid for the rest with the loss of your privacy. My advise is to put up no tresspassing signs, and a chain and a master heavy duty lock on the building and see what happens. It is up to you to decide whether to file legal charges. If it happens in the future you may want to look into finding another house.