Distributed systems and natural disasters: BitTorrent as a global witness

Peer-to-peer (P2P) systems represent some of the largest distributed systems in today's Internet. Among P2P systems, BitTorrent is the most popular, potentially accounting for 20--50% of P2P file-sharing traffic. In this paper, we argue that this popularity can be leveraged to monitor the impact of natural disasters and political unrest on the Internet. We focus our analysis on the 2011 Tohoku earthquake and tsunami and use a view from BitTorrent to show that it is possible to identify specific regions and network links where Internet usage and connectivity were most affected.