> From 2019 to 2021, Ricochet was used by the admins (as well as an undercover investigator) of the child porn onion site Boystown. To identify the perpetrators, German police used a correlation analysis attack. By sending Ricochet messages to perpetrators and monitoring several hundred Tor nodes for simultaneous traffic of the correct size, authorities were able to identify intermediate Tor nodes and then also the perpetrator's entry nodes, revealing the perpetrators' IP addresses.<p>From wikipedia.