We've recently started to notice that some of PCs connected to our domain are sharing the Users folder over the network. I've read that sharing any folder within the Users directory sets the directory itself to be shared too, but in all of the cases, Users is the only folder that is being shared. Furthermore, users shouldn't have the privileges to share anything. Public folder sharing is also disabled by the way.
Disabling the share is easy enough and I'm more interested in finding out the reason it has been happening.