[dazc]

A side effect of negative seo is that some stuff that hasn't worked on Google for a long time still does on Bing (They, Bing, obviously, not being the real target of the attack).

I've seen a few sites become de-indexed and the 'give away' is the type of results that first appear when the penalty is eventually lifted. For example, just a dozen or so urls with really weird query strings that never existed before. The real stuff does come back after time though and, in my limited experience, it's a one-off incident.

Just to add, not many sites are insignificant enough not to attract negative seo - especially this type of low-level, zero cost malarkey.