Except this isn't supposed to be investigating a leak, they're using a tool designed to ensure proper tax on imports.

19 USC 1509 has a catchall that extends the SHS's authority to compel documents to "insuring compliance with the laws of the United States administered by the United States Customs Service." [1]

It's definitely a stretch.

[1] https://www.law.cornell.edu/uscode/text/19/1509

If they could show probable cause, then they'd already have a warrant. They don't.

> If they can show probable cause that the owner of the account broke federal law, they have legal grounds to demand Twitter release his information.

They have a legal mechanism, too. It's called a subpoena. If I understand correctly, they didn't use that here.

Subpoenas are only available for investigations pertaining to an open court case.

Then file one.

Look, I care about limiting the power of the Federal government to the parameters outlined in the law and the Constitution. I do not care how hard that makes their lives. I do not care that it crimps their ability to go get any information that they want. They have rules that their supposed to follow. If they want the information, they should go follow them.

It isn't that hard to open a court case with a TBD defendant. If the USG thought they could get a subpoena, I have every faith that they could have figured it out.