kanetrain - 5:30 am on Jul 11, 2013 (gmt 0)
This exact thing happened to us en masse. Over 100K bad links targetting blog entries etc. over the course of several months. We have tried dissavow. Doesn't matter... we've been hammered by penguin updates over the last year. Maybe we should submit a reconsideration request?
The bad links keep pouring in (presumably they have set a whole army of bots linking to us) and are dilluting our link profile I am sure.
So depressing to feel that our rankings have gotten hammered because of stuff that is totally out of our control.
Negative SEO is very, very real.