courier - 6:06 pm on Apr 29, 2012 (gmt 0)
I agree, I was hit a year ago when my links rose from steady 4,000 for years to well over 100,000 in the less than a month, I am still sitting with 22,000 links.
Negative SEO has existed for years..
I did not add these and could do nothing about them. I have been running with a -50 since, although now an internal page appears on page 14, home page which was my main keyword moved from page 5 to page 28. Negative SEO worked then and it is still working now.