How does a grand jury get evidence? Grand juries can use the court's power to subpoena evidence. A court can issue a document known as a subpoena (a word which translates, essentially, as "subject to sanction") which commands someone to do something. The subpoenas are actually issued by the court clerk's office. The prosecutor will go to the court clerk's office and obtain blank subpoenas. The prosecutor then fills them in, putting in the name of the person or corporation that is being subpoenaed, and telling them what they have to do (testify or produce documents) and when they have to do it. The prosecutor then has someone--often a police officer or federal marshal--serve the subpoena on the person or corporation.
I believe a person can challenge a request under the PA although I'm not certain and I don't recall the procedure.
I believe a person can challenge a request under the PA although I'm not certain and I don't recall the procedure. The person's records being subpoenaed will never know that the event happened so he has not chance to challenge. Under the PA, the business or person subpoenaed cannot notify the subject.
In theory the business or person subpoenaed can challenge under the PA, but the power has been found by the court to be illusory as the standard to challenge was set so high under the PA that a challenger could never win.