Welcome to the future. All your radio frequencies are belong to me.
The HackRF is a Software Defined Radio (SDR) device.
It will allow me to transmit and receive all frequencies between 10MHz and 6GHz while using a computer to shape those waveforms. Normally only possibly with rooms full of expensive dedicated equipment.
When hackers got access to cheap SDR WiFi cards, that's when WiFi was broken (WEP/WPA/WPA2) and now it's time for everything from GSM phones, to 1970's satellites to come under scrutiny.
Incredible tools lead to amazing discoveries.
It's a great time to be a geek.