SharePoint 2010 + Explorer View and creating folders in the root

Users love the Explorer view, too much I find and there in lies my questions;

I need to prevent users from adding folders to the root of a site in Explorer view...anyone know how?

I do not want to exclude them fro using explorer view - its useful for them

I do not want to stop them creating folders within document libraries - again, useful.

But I would like to prevent the creation of a folder outside of a document library - is that possible or is this only going to be achieved with user training? Has anyone else worked around it or got experience on this?