Recently there has been intense focus applied to the issues of brand safety in digital advertising. Major advertisers and several media agencies are suspending activity on certain platforms until they can have absolute assurance that their ads will not run adjacent to violent, offensive, terroristic or pornographic content. Due to the gigantic scale of potential content and audience targeting options in digital media's long tail, there is much discussion of the development of filtering mechanisms that are exclusively machine based. These filters would use the kinds of predictive algorithms that have been so important in realizing the substantial ROI gains made through audience targeting in digital media. However, I believe a totally algorithmic solution, without human intervention or curation, is unlikely. Here's why.