It would be very helpful to have an option to make ArcGIS Online maps unsearchable, and therefore not visible on ArcGIS online outside of the organization unless you have a URL or it is embedded in a site (ideally, there would be an option for it to be visible only if embedded, with secure URL, but I don't know if that's possible). This would allow maps to be embedded in a secure website directory able to be displayed to everyone accessing it, but challenging to access in otherways.
I am having to go back and erase all the metadata, tags and descriptions so that the users can log on to the secure website directory but they cannot be easily found or understood in ArcGIS online. I think this may all be possible if I download the apps and maps and configure them offline and add them outside of ArcGIS Online, but it’s a bit of a hassle.
ISSUU online has a comperable security feature for sharing pdfs: http://help.issuu.com/hc/en-us/articles/204816088-How-to-upload-and-publish-unlisted-documents-Can-I-protect-my-publications-