rohitj - 2:15 pm on Jul 17, 2006 (gmt 0)

google will go through urls in referral logs as well. So if you ever visit a site, and it gets your ftp site as a referral, there's a possibilty that google may in turn get to your FTP site.

That's my understanding, since i've seen first hand that google had to have gotten my urls from referral logs. When i did searches, I eventually found a foreign referral log, listing the unique url in question.