The only insight we used to get into "bad people" was second hand, what people had seen and the things they had done. Now we get to see it all first hand. He has over 1,000 tweets from the last 18 months, Tweets that offer an insight into what he enjoyed, what he did, how he felt... we get to see him as a human. How many people saw Ted Bundy as a human? Maybe I'm overstating the value of his Tweets.