For the last year, Rigmaiden has claimed that his arrest was a result of a violation of his Fourth Amendment rights, which protects citizen from unreasonable search and seizure, because the government used a device called the stingray to track his cell phone without a valid warrant. The U.S. Department of Justice has stood by the defense that the use of the stingray is not considered a search because the user did not have a reasonable expectation of privacy while use Verizon Wireless cellphone service.
In the latest development of this case, the government is now admitting that the use of the stingray in this case could be considered a search and seizure under the Fourth Amendment. They are willing to make concessions specifically for this case in order to “avoid unnecessary disclosures” about the device. The judge in the case, David G. Campbell, has expressed the potential need for more information about the stingray before being able to determine whether or not its use can be considered a search in this case.
The FBI stated in a recent memo, it deletes all data from the stingrays because it tends to gather data on other mobile devices in addition to the suspect's. The FBI has stated that their intent is to ensure “the privacy rights of those innocent third parties are maintained.”
source: The Wall Street Journal