He says probable cause is required. Another great issue: Law enforcements use of "cell tower dumps" in which they get the subscriber info and cell cite locator data for every call using the same cell tower as their target. Hundreds of innocents persons' records are swept up. What do they do with them when the investigation is done? Do they remain in their database? The should be destroyed. Judge Owlsey writes

Finally, there is no discussion about what the Government intends to do with all of the data related to innocent people who are not the target of the criminal investigation. In one criminal investigation, the Government received the names, cell phone numbers, and subscriber information of 179 innocent individuals. See United States v. Soto, No. 3:09CR200 (D.Conn. May 18, 2010) (Memorandum in Support of Motion to Suppress).

Although the use of a court-sanctioned cell tower dump invariably leads to such information being provided to the Government, in order to receive such data, the Government at a minimum should have a protocol to address how to handle this sensitive private information. Although this issue was raised at the hearing, the Government has not addressed it to date. This failure to address the privacy rights for the Fourth Amendment concerns of these innocent subscribers whose information will be compromised as a request of the cell tower dump is another factor warranting the denial of the application.

From the Amicus brief in the Soto case:

The facts of this case demonstrate that the government is already using the available cell site technology not only to retrace the movements over time of those suspected of involvement in a crime, but to review the movement and associations of 180 individuals, some of whom could not have any possible connection to the investigation. These facts illustrate that "dragnet type law enforcement practices" that threaten to eviscerate privacy rights and chill associational and other expressive activities are now a reality. Knotts, 460 U.S. at 283-84 (reserving for another day the constitutionality of dragnet type law enforcement practices like twenty-four hour surveillance); United States v. Garcia, 474 F.3d 994, 998 (7th Cir. 2007) (permitting warrantless GPS tracking when the police have a suspect in their sights, but stating that "[t]echnological progress poses a threat to privacy by enabling an extent of surveillance that in earlier times would have been prohibitively expensive" and reserving decision on constitutionality of programs of mass surveillance), cert. denied, 552 U.S. 883 (2007); W.D. Pa. 2008 (Lenihan),534 F. Supp. 2d at 612 ("[N]ewly-emergent technologies create the potential to monitor associational activities in a manner that could have a chilling effect").

The Fourth Amendment protects an individual's reasonable expectations of privacy in information that he "seeks to preserve as private." Katz, 389 U.S. at 351. It cannot be correct that that Amendment has nothing to say about whether government, enabled by technology, may subject Americans to round-the-clock surveillance of their movements for as long as it likes.

Another good reason to turn off your location based services on your phone and not announce your presence at places on apps like four square: It's an announcement to the world that you are not at home.

So much to do, so little time. Here's an open thread, all topics welcome.