irishsolar - 4:45 pm on Apr 29, 2012 (gmt 0)
Negative SEO is just becoming more popular thanks to Matt Cutts over optimization statement. Another Google own goal IMO.
I've noticed it has been done on one of the sites I monitor that had already been hit prior to the backlinks becoming visible on WMT. Whether they were there prior to the update and whether google knew about them I can't say.
Inner pages on site are still ranking for main term that the landing page was optimized for (and which vanished from the SERPs) so how much damage those links are doing is impossible to judge at the minute