Note that you must have a Premium Creator account to make a resource private. For more information on Premium plans, see here.
When creating a resource, you can change the privacy settings by clicking the details tag.
You can also change the privacy settings by pressing the icon in edit mode.
If you wish, you can make all your resources private by default: Under Account>Privacy Settings, change the setting from Public to Private.
You can change the settings on individual resources at any time.