To the original poster, as I understand it, you are upset that a person copied the contents of your tree, meaning photos, documents, etc. The mistake wasn't in making your private tree public for your matches to see. It was making your peronal photos and documents availabe for someone to copy. I also have pivate trees, but I did upload a public version, just with no photos, etc. this way people can look at the tree with it's surnames, dates, and locations, but my personal items are still private. This is a simple solution for those members who dont want to open their private trees to dna matches.
I have to say, that I don't bother anymore with trying to contact dna matches with private trees. My research time is limited and I have such a poor response rate, that it is not worth my time. If their tree is private, I plunk it into the trashcan and move on.