God Bless our Troops.
"Normally, warrants require "probable cause" to believe that a crime is being planned or committed. But FISA warrants do not. They require only that the FBI show probable cause to believe that "the target of the electronic surveillance is a foreign power or an agent of a foreign power."
Prior to the advent of the USA Patriot Act, the law also specified that "the purpose" of a secret warrant must be counterintelligence (basically, spy-versus-spy activity). Now, however, intelligence gathering need not be "the purpose," but rather only "a significant purpose" of the warrant.
The "significant purpose" language opens the way for FISA secret warrants to be used for dual purposes -- one of which is simply normal criminal law enforcement. Indeed, the Bush Administration has defended, and the FISA Court of Appeals has upheld, this very practice.
And that, in turn, raises the specter of a possible end run around the Fourth Amendment. Spurious or ill-founded "counterintelligence" purposes might be used as a pretext to get warrants to spy, in a regular law enforcement context, even when probable cause of a crime is lacking."
As a criminal defense attorney this worries me. As a citizen it scares the crud out of me. Taking away the ability of the citizenry to have some sort of oversight - independent of government agents (whether they be judicial or law enforcement) - is dangerous and will eventually lead to abuse. We eschew dual use now but someone will get away with it (if reviewed at all the excuse will be good faith). Then it will (slowly) become a standard procedure available to law enforcement.