US authorities arrest suspect who used Tor to disguise his online identity and coerce underage female victims into sending sexually explicit images and videos in a tactic commonly referred to as “sextortion”” The FBI managed to catch the suspect in June 2017 after it created and deployed a custom NIT (Network Investigative Technique) that relied on appending de-anonymizing code inside a video file. FBI agents hosted the file on a Dropbox account shared by the sextortionist and one of his victims
Source: where with a judge’s approval they set up video surveillance and used a pen-trap device to intercept the Internet traffic coming and going from the suspect’s home.”