Everything the FISA process overseen by the Foreign Intelligence Surveillance Court and the Foreign Intelligence Surveillance Court of Review can authorize (and much more invasive means, contrary to your claim) can be authorized by regular search warrant.
The FISC process is used when the purpose is foreign intelligence rather than domestic law enforcement, and it exists because prior to that there was no limit on the covered activity when it was done for that purpose.
> Precedent exists, but nobody outside the national security state actually knows what it is.
The FISC process is used when the purpose is foreign intelligence rather than domestic law enforcement, and it exists because prior to that there was no limit on the covered activity when it was done for that purpose.
> Precedent exists, but nobody outside the national security state actually knows what it is.
Well, some of it.
https://www.fisc.uscourts.gov/public-filings
https://law.justia.com/cases/federal/appellate-courts/fiscr/