http://arstechnica.com/tech-policy/2016/03/appeals-court-no-stingrays-withou... [quote begins] On Wednesday, the Maryland Court of Special Appealspublished a legal opinion finding that state police must not only obtain a warrant before deploying a cell-site simulator, but are required to also fully explain to the court what exactly the device does and how it is used. As Ars has long reported, cell-site simulators—known colloquially as stingrays, can be used to determine a mobile phone’s location by spoofing a cell tower. In some cases, stingrays can intercept calls and text messages. Once deployed, the devices intercept data from a target phonealong with information from other phones within the vicinity. At times, police have falsely claimed the use of a confidential informant when they have actually deployed these particularly sweeping and intrusive surveillance tools. In recent years, stingray use has come under increasing scrutiny, with several states includingCalifornia, Washington, Virginia, Minnesota, and Utah now mandating a warrant be issued for their use. Last year, the Department of Homeland Security and the Department of Justice also imposed new policies that require a warrant for stingray use in most cases. In an e-mail to Ars, American Civil Liberties Union attorney Nathan Wessler called Wednesday's opinion the "first appellate opinion in the country to fully address the question of whether police must disclose their intent to use a cell site simulator to a judge and obtain a probable cause warrant." "The court’s opinion is a resounding defense of Fourth Amendment rights in the digital age," he continued. "The court’s withering rebuke of secret and warrantless use of invasive cell phone tracking technology shows why it is so important for these kinds of privacy invasions to be subjected to judicial review. Other courts will be able to look to this opinion as they address rampant use of cell site simulators by police departments across the country. [end of portion quoted] My opinion: The purpose of a "warrant" is to make legal what would otherwise be illegal. If an ordinary citizen used a stingray for this sort of surveillance, that would clearly be called illegal. Therefore, police should be required to obtain a warrant in order to use a stingray. (or, more properly, they shouldn't be allowed to do that at all.) Jim Bell