Anyone noticing huge SERP changes?

I've had about 30 domains for about 4 months. Many of them I didn't put any content on but because they were EMD's they were still ranking in the top 50-100.

Then yesterday I saw the rankings on EVERY single domain drop in increments of 100's, even the ones that I started putting content on and optimizing.

The domains are about 4 months old. Is this normal? Why in the world would it have happened to all of my domains at the exact same time? Kind of freaking out...

Are all of the domains on the same hosting account?

Yeah...

I read in lots of other places many other people saw same thing yesterday. I also noticed some big changes. Some went up, some went down, some stayed same. I think Google is testing something.

Interesting because Matt Butthole said once that Google won't go after
domains on the same hosting account unless it looks something like:
-1 legitimate domain and 300 spam domains

But with the recent talk about Google targeting autoblogs, I wouldn't be
surprised if they are honing in on them.

Then again, so many people used shared hosting that it seems
like a really time intensive process for Google to target these
types of hosting accounts.

Personally, I haven't noticed too many changes with my own domains.

But... About 90% of my content is unique w/ white hat seo.

I had one of my sites go down in rank by 50 - 100% on all the keywords it was ranking for.

Only thing I did was get 2 homepage links from 2 PR 4 domains and 1 PR 0 domain.

:i(

I found the problem...It's the new SERP Tracker SESScout that I've been using. If I knew how to post screenshots I would show you how ridicously wrong this thing was and how bad is scared me. The whole time none of the sites had moved. SEScout just went fucking bonkers on me. I realize its my fault for not going and checking manaualy, but checking 40 rankings of 496 or whatever they were isn't exactly fun...and that's the whole point of the software. I also realize it's in beta...But if it's in Beta, why in the hell are they going to charge you?

A couple of quick notes:

All of the sites are whitehat as it gets...while some dont' have content on them, most do. there's no over-optimization whatsoever.

OMG!! I thought i was the only one who faced this heat checkout my thread here http://www.blackhatworld.com/blackhat-seo/white-hat-seo/274706-need-help-lost-rankings.html

it was my main earner ... i wish it comes back