A few months ago I was tinkering with putting a wiki on my site. I played around with it and decided it wasn't worth it. I abandonded it without removing it. Big mistake.
The only place where I told anyone where the wiki was is where you signup with WikiMedia.
Sometime within the last 30 days, an <adult content> spammer got ahold of the wiki and managed to post 60+ pages and videos of adult content. I logged into Google Webmaster tools and saw our incoming links had increased by a factor of 100. I soon discovered that the new pages were at example.com/wiki/skins/simple/img/*.*
We've been hit with a loss of rankings in the past couple of weeks which I attributed to a algo shake up but I'm more convinced I lost rankings because of this. The wiki page backlinked to the home page but no other pages on the current site referenced the wiki at all.
(1) Removed all wiki pages.
(2) Modified robots.txt to disallow all robots to the /wiki directory.
(3) Removed all offending URLS using the Google URL removal tool.
(4) Submitted a reconsideration request to Google explaining what happened.
Anyone have any other ideas that I should do.
[edited by: tedster at 8:16 pm (utc) on May 12, 2008]