Great article about World Cup moments when Twitter goes silent: "Just before the holiday weekend, Miguel Rios, data science manager at Twitter, posted a blog showing how Twitter users behaved during the penalty kick shootout during the Brazil vs. Chile match on June 28... Twitter describes the deep valleys (in activity during the shootout) as “silences,” while the large spikes that follow show how users reacted to each kick." Check it out- http://www.mediapost.com/publications/article/229518/making-noise-when-twitter-goes-silent.html