Man that is a pile of stands to find! Can you tell if they were newly set? I am assuming they are fixed position stands with tree steps in the tree's.
If the land wasn't posted and these folks have been hunting there for years,I am sure they wont be very happy.
I would pull the stands and the steps and put them at the base of the tree with a note on them,put the note in a zip lock bag.The note would say some thing to the effect that you are sorry to disrupt their hunting but the land owner has decided to post his property and not extend permission to others to hunt it.You are sorry for any inconvenience created for them.
This way they are far less likely to hunt any of the stands or re-set them.It also shows that you are being respectful and havn't taken their property.
That would be my first step.