Stingray technology, also referred to by investigators with a confusing array of other names including "WIT" and "Triggerfish," is interesting and creepy stuff. It mimics cell phone towers to get mobile devices to reveal their locations, turning your handy widgets into tracking beacons. The technology is controversial because courts are generally unfamiliar with the devices, and there's growing evidence that they're being used by law-enforcement agencies who obtain authorization for their use by peddling them to jurists as older, much less-intrusive technology, when they bother seeking permission at all. The LAPD was caught presenting stingrays to judges as "pen register/trap and trace," which dates back to the days of operators and land-line exchanges. Now, as noted at Reason 24/7, the American Civil Liberties Union has unearthed evidence that the feds have been doing the same thing — so frequently, in fact, that judges have become annoyed and the United States Attorney for the Northern District of California is trying to get a handle on the practice.
In the process of gathering information about the use of stingrays in the case of United States v. Rigmaiden, the ACLU obtained several internal Justice Department emails. The first email in the series, sent to the USACAN-Attorneys-Criminal mailing list on May 23, 2011, says in part:
Effective immediately all pen register applications and proposed orders must be reviewed by your line supervisor before they are submitted to a magistrate judge.
As some of you may be aware, our office has been working closely with the magistrate judges in an effort to address their collective concerns regarding whether a pen register is sufficient to authorize the use of law enforcement's WIT technology (a box that simulates a cell tower and can be placed inside a van to help pinpoint an individual's location with some specificity) to locate an individual. It has recently come to my attention that many agents are still using WIT technology in the field although the pen register application does not make that explicit.
The rest of the email makes it clear that higher-ups have no idea as to the extent of stingray use, beyond the fact that it's common.
Another email makes it clear that using stingray technology was sometimes the initial intent of a pen register application, and other times it was just dropped in as a matter of convenience. "In other words, a pen might have started out as just a pen, and later the agents decided to use the order to also attempt to locate the target," the author suggests with a fine regard for plausible deniability. "They may or may not have told you about this decision. So check in with your agents to find out if they have been using pen register orders to locate targets with the WIT boxes, whether or not they started out intending to do so."
Who knew that warrants were so … elastic? Well, aside from the agents stretching them to acommodate powerful new surveillance technologies, that is.
On the plus side, judges apparently are catching on and trying to reign-in rein-in* some excesses.
* Yeah, yeah. My bad.