I would guess a lot of that happens in the public for transparency reasons; if one reporter (or otherwise just curious citizen) notices that (as an example) the

I would guess a lot of that happens in the public for transparency reasons; if one reporter (or otherwise just curious citizen) notices that (as an example) the Honorable Cacheris starts sentencing more harshly than their peers, or letting off CEOs in their courtroom with a "stern talking to," then that would be worthy of an investigation I'm sure the Justice Department's point of view of press releases is one of deterrence: "do the crime, do the time" or perhaps even "your tax dollars at work"