So what happens when said site is hosted by a legitimate web host which acts on complaints? You end up driving up said hosting company's bandwidth bills and (more importantly) very likely taking down other sites on the same webserver instance.
Also, in case you hadn't heard, spammers often use bogus CC info, don't pay their bills, etc.
How about only taking action if the URL remains active for a couple days or more, indicating a lax hosting company?
And, for anything like this to work (and again, I still argue that this isn't the right approach), you need to have a lot of people hitting the site all at once, which conflicts with doing all of these checks in a reasonable and safe way.
I recall seeing a site that set up a web page that used JavaScript to rapidly reload images from a well-known offender. The idea was to get lots of people visiting that page so that they'd start hammering the spammer's site from many IP's.
