@indigomoth - It's funny how that letter can change a person's attitude. I've had to deal with someone who had become a stalker of sorts after we had a disagreement. He kept sending me all kinds of nasty emails and letters and threats and things.
Once I was able to send him a legal letter of representation the threatening notes suddenly dried up. It was almost too bad that they did, since I probably could have used them later on, but it was such a relief to know that I didn't have to worry about it any more. Say what you want about lawyers, it's wonderful to have a good one on your side.