Just a FWIW, we know we're supposed to do a thorough site clean-up before sending in a "reconsideration" request, though that may now also include cleaning up any spammy comments left on third party sites.
"Similar to how you have removed spammy links in your own forum, you
may want to consider what you can do to help clean up similar links on
other people's sites."
John Mu, message 74
Please Help! -60 penalty from Google due to proxy site. - Crawling, indexing, and ranking | Google Groups
With thanks to Sebastians Pamphlets for highlighting this.
"Similar to how you have removed spammy links in your own forum, you
may want to consider what you can do to help clean up similar links on
other people's sites."
John Mu, message 74
Please Help! -60 penalty from Google due to proxy site. - Crawling, indexing, and ranking | Google Groups
With thanks to Sebastians Pamphlets for highlighting this.