To a certain extent, the criminal investigation is a way to ensure justice is served, provided that it leads to the perpetrators being nabbed, the evidence being used to successfully prosecute them and their being punished, mainly sent to prison.
That said, data on the black market represent virtual assets, ones that aren't housed in a physical location. Data can be located in many places. I'm not trying to alarm people, but it's important for them to understand that, even if the perpetrators are arrested, it doesn't necessarily mean that their data are no longer vulnerable and their identity can be restored.