Tor as you may know per its website https://www.torproject.org/ is free software and an open network that helps you defend against a form of network surveillance that threatens personal freedom and privacy, confidential business activities and relationships, and state security known as traffic analysis. While tracking this you can see the number of Tor users spiked in certain countries after the news in reference to PRISM and NSA spying programs were distributed
You can access this information here.....https://lists.torproject.org/pipermail/tor-censorship-events/2013-June/thread.html
You can access this information here.....https://lists.torproject.org/pipermail/tor-censorship-events/2013-June/thread.html