This is the option I believe that would cause your doc to be indexed:
<i>Allow anyone with the link to view (no sign-in required)</i><p>Simple as that. Just don't check off this option when sharing.<p>I don't know why everyone is so worried about this security wise.
As people have pointed out, it is fairly easy to keep your stuff private still, but this does represent 'one more thing' that you need to do to ensure personal privacy. There is getting to be more and more overhead online taken up with making sure you have all the correct boxes checked/unchecked in order to ensure privacy. Facebook being a great example of a really obtuse system. I wonder what kind of startup opportunities these companies will carve out for little guys as they continue to slide towards the 'we own your data' side of things - after a certain point more and more people will desire a simpler, more private set of tools.
Worrying. Even if by accident, private or confidential docs could end up listed in Google's search results. There surely will be cases of this happening.<p><a href="http://www.timacheson.com/Blog/2009/aug/google_apps_are_a_risk_for_business_users" rel="nofollow">http://www.timacheson.com/Blog/2009/aug/google_apps_are_a_ri...</a><p><a href="http://www.elasticvapor.com/2009/09/is-privacy-in-cloud-illusion.html" rel="nofollow">http://www.elasticvapor.com/2009/09/is-privacy-in-cloud-illu...</a>
Why not send an email to each domain with a list of everything they find? Or create an administrative 'audit' tool that will show all domain documents that are being shared publicly.<p>Do that a month or so before they push the hits into Google results and no-one would have any reasonable basis to worry or complain.