The FBI used a network investigative technique (NIT) to unmask a sextortionist that via Tor was threatening youngsters. The FBI arrested Buster Hernandez, 26, who was charged with multiple counts of sexual exploitation of a child, threats to use an explosive device, and threats to injure. The man was using Facebook to lure the young victims and extort them to send him pictures of themselves naked. He is suspected to have sextorted a number of victims in at least 10 federal districts.”]
Source: http://securityaffairs.co/wordpress/61850/cyber-crime/fbi-nit-sextortionist-tor.html