This is not something you can reason about from first principles. The parent is talking about how the DoJ actually operates, not a theoretical construct. That

This is not something you can reason about from first principles. The parent is talking about how the DoJ actually operates, not a theoretical construct. That said, most warrants to collect evidence are not issued to the DoJ, they are issued to state and local prosecutors, who are often more aggressive than DoJ is (in part because so many AGs are elected, IMO).