My duty is managing an ArcSDE geodatabase. I think ArcSDE supported security mechanism is very good. My staff only can access ArcSDE geodatabase via ArcMap with MXD file created by me. But problem is they can export ArcSDE geodatabase to shapefile from ArcMap interface. So, I think we should eliminate exporting data function in ArcMap or don't support this function with source database from ArcSDE geodatabase to upgrade security level.