dstiles - 7:52 pm on Jun 27, 2013 (gmt 0)
I think "add a site" would be less spammed than auto-find by crawling.
I would only expect a small percentage of users to hit the "spam" button but that's still better than none.
One anti-spam method for both "add a site" and crawl may be to pay attention to the various reports of evil DNS and domain name registrars. Both can be discovered to at least a reasonable degree (which is why I do not understand the domain registration agencies failure to pick up on this).
A vast number of the domains registered and dropped each day are registered by criminals and a fair number are used for virus-serving sites for a few days before being rumbled; and some of the more robust ones find their way into search engines. Something else that domain registrars could detect and deflect.
Anti-spam/virus measures on an SE would need someone permanently assigned to the problem; that could be a downer on a start-up.