The software has been met with criticism from civil liberties advocates, especially given that its WebLoc add-on enables warrantless device tracking. Normally, when U.S. police officers seek cell phone records or location data, they must obtain a warrant by presenting probable cause of a crime to a judge. In 2018, the U.S. Supreme Court ruled in Carpenter v. United States that warrants are required for obtaining location data from cell phone providers. But the rise of the multi-billion dollar data broker industry has created a free-for-all that enables police and others to purchase massive amounts of cell phone location data without judicial review.
Nathan Wessler, an ACLU attorney who argued the Carpenter case, said data broker-built services like Tangles pose the same privacy issues as those decided in the Supreme Court case and that law enforcement’s ability to buy location data constitutes an erosion of constitutionally protected rights. “Police are doing an end run around this well-articulated system of judicial oversight by just paying money instead of going to a judge,” he said. “There’s just no checks of police abuse against that.”