Sorry, I’m not seeing the part of the law that allows an ALJ to permit this (which makes perfect sense - title 18 is the criminal code and crimes can not be prosecuted in administrative proceedings generally). The statute seems to contemplate only district courts and state courts, neither of which are “administrative.” Where are you seeing a reference to an ALJ being able to issue one of these, particularly in a criminal case?

[1] Federal Trade Commission (FTC) - FTC v. Innovative Marketing, Inc., the court allowed the FTC to use administrative subpoenas in a criminal case involving fraudulent business practices. The court found that the information requested by the FTC was relevant to the criminal case and that the use of administrative subpoenas was an appropriate means of obtaining that information.

[2] Department of Justice (DOJ) - In United States v. Parris, the court allowed the DOJ to use an administrative subpoena to obtain information from a bank in connection with a criminal investigation. The court found that the DOJ had the authority to issue administrative subpoenas under the Bank Secrecy Act, and that the information requested was relevant to the criminal case.

[3] Securities and Exchange Commission (SEC) - In the case of SEC v. Jerry T. O'Brien, the court upheld the SEC's authority to issue administrative subpoenas in connection with a criminal investigation. The court ruled that the SEC could use administrative subpoenas to obtain information that was relevant to the criminal case.

[1] https://casetext.com/case/federal-trade-commission-v-innovat...

[2] https://law.justia.com/cases/federal/district-courts/FSupp2/...

[3] https://caselaw.findlaw.com/us-supreme-court/467/735.html

These cases do not say what you think they say. Please cite to the actual parts of the decision that discuss the legality of administrative subpoenas issuing for a criminal case rather than the admissibility of information provided in response to a civil subpoena by a third party. Recall that we are talking specifically about the use of a pen register in a criminal case brought by the DOJ, not random regulatory compliance required in highly regulated industries.

The FTC case is a civil case. The DOJ case does not even mention the word subpoena as far as I can see. The SEC case is a civil case.

He's been arrested and charged, and he had been specifically ordered to not use encrypted communications methods by the court as a matter of his bail.

It makes perfect sense that they'd be monitoring his communications to ensure he was in compliance with that order.