My only issue with those who have used the information I post - when they attach it to the wrong person, with a similar name in a different location, different century. That information then proliferates to multiple other trees.
If someone uses my post in a private tree, I don't know if they have attached it to the same person or to someone with another name.
I usually try to contact someone who has copied information from one of my trees to a private tree. If they don't respond or don't choose to share, I have better things to do with my researching time.