The items displayed in Virto Calendar are visible for calendar users according to SharePoint security settings. If there are special access settings for every SharePoint list’s items, they will be applied to these items in the Calendar.
For example, users with no access rights to items of List 1 will not see these items in the calendar. If they have rights of List 2 item management they will be able to move, edit, resize and etc. these items in Virto Calendar. And if they have just read-only rights applied for List 3, they will be able to view items of this list in the Calendar but will have no ability to change any information of them (edit, resize, move, delete).