Hours after BuzzFeed News published this report, City Hall asked Titan to remove the devices, which could have been used to push ads — and track phones.A company that controls thousands of New York City’s phone booth advertising displays has planted tiny radio transmitters known as “beacons” — devices that can be used to track people’s movements — in hundreds of pay phone booths in Manhattan, BuzzFeed News has learned. And it’s all with the blessing of a city agency — but without any public notice, consultation, or approval.