I was recently surprised to discover that documents I had stored on my personal web space with my isp were searchable by google. I mistakenly assumed that this was like cloud storage and only accessible by me.
I wonder how many others have made the same mistake.
Having seen your posting Lionel I did a Google search with my name and found my images from a website, 500px, showing in the results. I hadn't, or so I thought, made them 'public'. I have deleted them. Thanks for the posting, Roy.
I have since had a reply to my query from my ISP and they informed me that the web space was intended to hold web sites etc and as such was not hidden from search engines. Perhaps they will make this clear in the near future.
If there's content on your website that you really, really don't want anybody else seeing, your best bet is to password-protect that directory. There will usually be a tool to help you do this in your hosting control panel (cPanel or similar). Note that password-protecting your comment (if done right) will also prevent the unpolite bots from accessing the content
Here's another interesting link which says what you did should not happen provided:
1. Your webserver is not supporting directory listing services as a default state.
2. If an index file such as "index.html, .htm, .php, .asp" or
"default.htm, .asp" is present in the folder root then the server will
refuse to give out a directory listing.
3. Your document is not getting picked up in Googles searches for specific file types?
Well, there's little more I think I could add without further internet research on the topic.
If you do want to temporarily share your (large) files across the internet (privately), something like DropBox might be better way. You can even share it to others who are non DropBox users.