I'd go one step further than "Even more so, why are you verifying a site that is borderline spam with Google in the first place?" -- Why are you spending time creating and promoting spammy sites in the first place? Seriously, why not just spend that time working on quality sites for the long run instead? :-)

Make great sites, not spam.

John, no such thing as great spam? :-)

PS If these are clean sites, I would recommend posting in the Google Webmaster Help forum with some of the actual URLs so that any issues can be diagnosed and resolved. Discussing them without URLs is somewhat difficult.

I am reminded of a comment Matt Cutts reportedly made at a PubCon (I think) a few years ago, where someone complained that his new site wasn't doing well. Matt supposedly looked up some information on his magic GooglePC and found there were many identified spam domains that he controlled. Matt said something like, "If you create 200 spam domains, we're probably going to take a closer look at your 201st domain."

I'm not suggesting that whomever complained about "clean sites" all being penalized necessarily violated any guidelines. But it does appear to me that Google has its ways of figuring out whether you're operating a network.

Not all networks are bad but bad networks can certainly spread their karma.

Rankings fluctuate. You hear stories like this because webmasters don't post to forums to bitch because their rankings went up.

@JohnMu.
"Why are you spending time creating and promoting spammy sites in the first place."

Sorry to be blunt, but the answer is simple: IT PAYS. You make Google infallible to spam so that no spam site would ever be promoted to the first page, and you won't see any more spam. Until then, it will be like this.

I recently saw a serp for a prescription drug, where 6 out of 10 results were from .edu pages, and all redirected to the same site. They stayed there for 1-2 days maybe, but it pays (though less). And you know they were software generated, so no cost. Again, it pays.

Something else which could be a part of the issue (and is something that is more common than you would imagine) is that there are technical issues surrounding the change in rankings. That could be as simple as a malware-infected server or as complicated as a server accidentally cloaking to Google's IP addresses. By posting the URLs involved in our help forum, we (and the other expert users there) can take a look and check to see what's really happening.

However, without a URL, all speculation is useless. :-)

This is really scary... Does that mean one bad move on your behalf and you're doomed for the rest of your life ??? I know Google is really unforgiving on some issues... I'd rather create multiple accounts...

I doubt Google is doing this, and if they are it's only to take it into consideration when it's extreme like Michaels comment explained. I have multiple sites in one account, and many of them are for clients that I take care of, and I have yet to see a relation.

No URLs. There isn't much to discuss about.

Well, it does sound scarry! Google should state clearly what their intentions are. But then again, do they ever? :)

Certainly very interesting. Search engines have been know to hand filter results, so anything is possible. The best defense is to put out quality websites and not worry about anything coming back to bite you.

The definition of SPAM has always been in the eye of the beholder. What I , Barry, John, Michael and Google think may constitute SPAM is probably completely different.

I know some people doing spam. And when i sometimes what they are earning i'm asking myself "why did you start with this white hat site some years ago?" It's still a fact that spammers are earning much more than the honnest webmasters...