What can be done when a new neighbour moves in, and immediately places things in your yard?

My new neighbour moved in and within 2 weeks has moved his shed to a location that straddles the property line and parked a trailer beside it. I confronted him asking him to move the trailer, I shoed him a copy of the most recent Platt available in the local Platt office. He ignored this and stated he believes it is his property and will have it surveyed, meanwhile he is leaving it there... He included a threat that I would be sorry if I have it moved.