[Infowarrior] - Court: Cops Need Warrant for Cellphone Location Data

[Richard Forno]

Cops Need Warrant for Cellphone Location Data, Judge Rules
By Ryan Singel EmailSeptember 11, 2008 | 3:51:08 PMCategories:  
Surveillance

http://blog.wired.com/27bstroke6/2008/09/cops-need-warra.html

The government cannot force your cellphone provider to turn over  
stored records about your location without proving to a judge there is  
probable cause you have violated the law, a federal district court  
ruled Wednesday.

The ruling (.pdf) from Judge Terrence McVerry of the Western  
Pennsylvania U.S. District Court deals a blow to investigators who  
have been getting cellphone location data on in the past simply by  
proving to a judge that the information would be relevant to an  
investigation. That's the same standard used to force a telephone  
company to reveal the name and address of a subscriber.

McVerry upheld a February decision written by five magistrate judges,  
who found that the government's request for historic cellphone  
location data for a person required a stricter standard. Little is  
known about how often investigators ask for such data, since the  
hearings are one-sided and the decisions are almost never published so  
as not to tip off the targets.

However, the ruling does not hold force across the country, and as the  
government's objection to the ruling noted, other judges have  
disagreed with the logic of protecting this data as if it were very  
sensitive.

The orginal decision(.pdf) found that "location information so broadly  
sought is extraordinarily personal and potentially sensitive; and that  
the ex parte nature of the proceedings, the comparatively low cost to  
the Government of the information requested, and the undetectable  
nature of a [cellular service provider]'s electronic transfer of such  
information, render these requests particularly vulnerable to abuse."

The government appealed, arguing the records only reveal a phone's  
location when it is actually used and that there's no constitutional  
right to have these stored records protected.

"Wireless carriers regularly generate and retain the records at issue,  
and because these records provide only a very general indication of a  
user’s whereabouts at certain time in the past, the requested cell- 
site records do not implicate a Fourth Amendment privacy interest,"  
the government wrote (.pdf).

But the friend-of-the-court brief (.pdf) from the Electronic Frontier  
Foundation and the Center for Democracy and Technology and others  
disagree -- arguing that law enforcement wants the data to pinpoint  
where a person was or is and that the data will only get more precise  
in the future.

"Law enforcement uses the fact that the suspect’s phone contacted the  
cell tower nearest his home to infer he is home, nearest the  
narcotic’s kingpin’s house to infer that they are together, nearest  
the drop off point  to argue that he was present when the contraband  
was delivered," the groups wrote. "One can also imagine that the  
government can ask for all the numbers that made calls through the  
tower nearest a political rally to infer that those callers attended  
the rally."

The distinction matters since generally speaking police officers don't  
need a warrant to plant a tracking device on a car, unless that  
vehicle goes onto private property. Tracking someone onto private  
property requires a warrant.

As for what the police need to prove to a judge in order to turn your  
cellphone into a tracking device -- that's a question that federal  
judges remain split on, despite the Justice Department's own  
recommendation that investigators get warrants based on probable cause.