This doesn't account for users who have never submitted or commented, because there would be no way for their profile URLs to end up in Google's index. Or am I

This doesn't account for users who have never submitted or commented, because there would be no way for their profile URLs to end up in Google's index. Or am I missing something? I know that there's the possibility for things to get into the index through the Google Toolbar, but I suspect that the fraction of HN users who use the Google Toolbar is quite low.