Israeli startup Taykey has developed a tool that enables advertisers to prevent their ads from appearing on malicious websites. It checks a site is safe for the advert to be hosted.  In 2016, offensive websites earned hundreds of millions of dollars by sharing profits with advertisers.

http://www.jpost.com/Business-and-Innovation/Tech/Israeli-technology-prevents-ads-from-financing-terrorist-websites-488287

https://www.youtube.com/embed/W59E3vdrKb0?rel=0