https://qz.com/1177168/dear-google-please-stop-using-my-advertising-dollars-to-monetize-hate-speech/

My company sponsors online hate speech, fake news and racist propaganda. It’s not that we are trying to—and given the small budget of the engineering company I run, my contribution may only amount to pennies a month. But in total, online advertising accounts for tens of billions of dollars annually, so even tiny percentages mean millions of dollars directed from the bank accounts of advertisers to the pockets of Holocaust deniers, Sandy Hook hoaxers and promoters of vile, racist content.

The reason advertisers like me inadvertently sponsor and monetize hate speech is that ad-tech companies like Google have partnerships with publishers who allow and promote this type of content. And unless advertisers proactively identify and block objectionable sites as I try to do, their ads may appear there.