I was running an algo-penalised site through majesticSEO when I noticed that in the historic index i've had 11k backlinks deleted(gone missing). Up to now i've been a little stumped as to why i got penalised as the content is fine and it has a ton of backlinks. I got no unnatural links message and after placing a reconsideration request Google told me i hadnt been hit with a manual penalty, it was an algo penalty. But logically, if you were a webspam engineer at Google, coding the algo, then i'm sure you would use the amount of dropped links as an indication that a website is spaming across the net. I was using scrapebox with highPR lists from linkloophole. I was bombing the whole list straight to moneysite. When a site eventually dies because of all the spam, all those links are deleted, Googles sees this and eventually you get a penalty for spam. I've changed my tactics now, so that when using scrapebox I only post once to each domain in the list. That way, when a site dies you don't lose 200+ links, you only lose one. So if you've been hit with a penalty, check what majestic SEO says about how many deleted link you have.