> In the hands of a black-hat SEO, these were the key to the castle, as you could now target negative SEO attacks at your competitors to amplify existing penalties they had. It would have been very difficult for victims of such a targeted attack to recover.
This needs some more explanation. How can I use the fact that another we site is penalized.
Yeah I wouldn't call it keys to the castle. But you can confirm your competitor has a penalty, and if they do run a negative SEO campaign (bad links) and to make it harder for them to get out of
