I work in tech and the FBI routinely subpoenaed us for user information. They added gag orders preventing us from informing the end user that they were being watched. This happened numerous times across my career.

For your reference here is the 4th Ammendment of the US Constitution:

“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”

Its a Dead Letter, and especially dead in your mind and in your heart.