As someone who for the past several years has done very high end legitimate SEO consulting to fortune 500 style companies (i.e. not the spammy mess than the HN

As someone who for the past several years has done very high end legitimate SEO consulting to fortune 500 style companies (i.e. not the spammy mess than the HN crowd would usually associate with SEO), I am more than happy to go on the record and say that for what it's worth, this is the exception and not the rule. As a few others here have pointed out, slapping Google Authorship markup all over your site is probably not a good idea unless you run a pure news / blog style site. One other point to note though as well is that I am very familiar with that message in GWT telling you that traffic dropped by a crazy percentage overnight. Given everything going on in the SEO space at the moment, I am not entirely convinced just yet that you don't have a case of correlation rather than causation at the moment.