so far not one single private tree owner I have messaged has bothered to respond. One of them showed that there was a matched ancestor. All I asked for was who the shared ancestor was.
To make matters worse I discovered a different private tree owner had taken things from my tree. I think that as a condition for keeping your tree private you should also be locked out of public trees.
I completely agree that Ancestry should at least give us the common surnames and/or any matched ancestors names.