http://www.businessinsider.com/ai-could-fix-cyberharassment-and-porn-on-the-internet-2015-7

SRI’s AI systems build on the company’s past expertise on how people communicate online using supervised machine learning. According to Wired, 250 people curated online harassment data from an anonymous social network and fed it into the AI system. Over time, the AI learned what words and phrases constitute harassment.