Page Rank Penalties after GWT notice of ON site unnatural links

[Algoholic]

Has anyone been seeing the huge numbers of sites losing PR lately? One of my sites was dinged and I got this Google love letter via Google Webmaster Tools (GWT):

Google Webmaster Tools notice of detected unnatural links on
http://domain.com

Dear site owner or webmaster of http://domain.com/,

We've detected that some of your site's pages may be using techniques that are outside Google's Webmaster Guidelines.

Specifically,

...look for possibly artificial or unnatural links on your site pointing to other sites that could be intended to manipulate PageRank.

Examples of unnatural linking could include selling links to pass PageRank or participating in link schemes.

We encourage you to make changes to your site so that it meets our quality guidelines. Once you've made these changes, please submit your site for reconsideration in Google's search results.

I had been allowing a lot of guest blogging on that site and was liberal with how guest authors linked out. I think that this is why I got this message. But I did not lose rankings, just lost PR completely. So I nofollowed all the links and sent a reconsideration request.

Anyone else seeing sites that allow alot of guest blogging losing their PR? I've confirmed this with others I know who operate or work with thousands of sites and they are all seeing this too, freaking out. So for me I have massive confirmations of large numbers of sites losing PR. But no one is talking about it anywhere that I can see.

I think this may be part of Penguin 2.0.
.

[edited by: Robert_Charlton at 1:59 am (utc) on May 22, 2013]
[edit reason] disabled auto-link to make example link visible, fixed formatting [/edit]

[cabbie]

Check this thread
[webmasterworld.com...]

I have sites that only link to other of my sites that have been pinged.
Relevant fields but links in are in side panels under Other resources type heading.
Some sites have had their pr halved, others zapped altogether.
Follow Links are out according to google(it seems).
No follow links are in.
Be ware of the Google monster that ate the world wide web

[edited by: tedster at 11:26 am (utc) on May 22, 2013]
[edit reason] fixed link [/edit]