The British General Warrant was the most hated aspect of British rule over the American colonies. British soldiers would enter homes and seize firearms from the colonists pursuant to a General Warrant, and that is what began the American Revolution and resulted in the 4th Amendment.

British “Writs of Assistance” purported to authorize the search of any place in which the Crown’s agents thought smuggled goods might be hidden. Boston merchants challenged the Writs in court in 1761, and attorney James Otis argued that the common law banned general warrants. Otis lost the case against the Crown, but his argument was popular in the increasingly rebellious colonies.

As a result General Warrants defined as those without probable cause, or failing to specify things to be seized or places to be searched, are banned by the Constitution.

The first half of the 4th Amendment bans “unreasonable searches and seizures”, and the second half, known as the Warrant Clause, requires a search warrant supported by an affidavit signed under oath showing probable cause that a crime was committed and specifying the places to be searched and the things to be seized. Without the allegation of a specific crime being committed, there can be no valid warrant.

So the entire NSA domestic spying program is illegal under U.S. law. FISA court general search warrants are illegal precisely because those were the reason why the 4th Amendment was written. Public officials should be placed on trial for what the NSA has done.