How to make a $7 cellphone sniffer

Tracking cellphone signals is much, much easier than you think. This demo from Danish IT pro Keld Normal uses a $7 USB device to snoop in on cell signals, essentially sniffing out any cellphones connected to a tower nearby.
There’s a lot of Ubuntu and Python stuff going on under the hood, but it’s not as complicated as it looks. The USB doohickey is basically an antenna, picking up signals as they pass between phones and cell towers. This won’t get everything, but it’ll g