The October 1 closing of a popular darknet marketplace leaves a big hole in the billion-dollar industry of illegal drugs, credit card and bank fraud, forged documents and more.

Three MuckRock users filed FOIA requests from 2013 to 2015 for FBI files on The Tor Project, Inc., the developer of Tor. The software enables (in theory) untraceable access to both the regular internet and a network of websites inaccessible through other browsers, commonly called the “dark web.” Each request returned radically different sets of records, most predating the first request, and all linked only by their lack of substantial information.

Runa A. Sandvik is a privacy and security researcher, working at the intersection of technology, law and policy. She is a Staff Technologist at the Center for Democracy & Technology in Washington, D.C., a Forbes contributor, and a technical advisor to both the Freedom of the Press Foundation and the TrueCrypt Audit project. Prior to joining CDT, she worked with The Tor Project for four years.

Recently released documents detail the federal government's inability to pursue cybercriminals shrouded by the tricky anonymity tools used by the Silk Road marketplace and other darknet sites - tools which are funded in part by the federal government itself. In this particular case, a citizen reported stumbling upon a cache of child pornography while browsing the anonymous Tor network's hidden sites.