How are sites rated for Safe Search

I was looking for USPS tracking and the first site that came up "usps.package.tracker.alot.com" (a Sponsored SIte no less) is an obvious scam and spyware site.  (I hope) the combination of Firefox and Norton protected my computer.  Why does this site have a green rating and is a sponsored site?  I hope I am not paying Symantec to take money from scammers and list their web pages.  And when you go to the Safe Search page for this site, there is no way to dispute the rating (other than join the 9 other people whose complaints are falling on deaf ears)