voters. that firm cambridge analytica denies violating facebook's terms. cnn media correspondent brian joins me now. a lot of layers. help us make sense of it all. >> yeah, all involves cam bren and anayltica, mysterious firm that helps campaigns and other organizations target voters, to try to figure out what you as a voter wants to hear at a given time and deliver that ad to you. so cambridge analytical has been selling those services for years. and ts trump campaign along with the ted cruz people bought cambridge services back in 2016. so go back a little further. cambridge analytical in infancy partnered with professor who happens to work at cam bren university, no relation to the company, who created this personality quiz. created this app on facebook. listen i've done some of these. you've probably done some of these. most of these fine. no evil purpose behind them. but in this case this