Robert_Charlton - 7:57 pm on Jun 6, 2012 (gmt 0)
Matt is most likely talking here about links that were completely unsolicited, not about links that you just wish you hadn't bought. It's hard to say what the forgiveness factor would be on those. The relevant quote from the article...
...People have asked questions about negative SEO for a long time. Our guidelines used to say itís nearly impossible to do that, but there have been cases where thatís happened, so we changed the wording on that part of our guidelines.
Some have suggested that Google could disavow links. Even though we put in a lot of protection against negative SEO, thereís been so much talk about that that weíre talking about being able to enable that, maybe in a month or two or three.
More in the SEL article on this worth reading.