Learn about safely measuring the Tor network in this conference talk presented at CCS 2016. Explore the challenges and importance of measuring Tor, understand the use of circuits and directory authorities, and discover PrivCount - a secure measurement system. Gain insights into the initialization, configuration, and execution of PrivCount, as well as its security features. Examine the collection phases and analyze results related to exit policies and the number of unique Tor users. Delve into the research conducted by Rob Jansen and Aaron Johnson from the U.S. Naval Research Laboratory, presented at the 23rd ACM Conference on Computer and Communications Security in Vienna, Austria.