hidden page to crawl

[whl626]

I wonder if search engine spider can crawl a hidden page ? That means there is no link to it inside the website ? If it can, does that mean it gains access to one's ftp and opens the file inside to crawl ?

Tell you something, from my experience as I tried out. I used the same hidden page, for instance ' abc999.html ' . And I changed its content, and the next day Google adsense shows different ads relevant to the theme of the content.

Can someone give more info on this thing ?

[Pic]

If the page is loaded with the google code, a bot will come and crawl the file... links or not.