[!WARNING]
This is not intended to be legal advice and should not be construed as authoritative, accurate or complete for your or any jurisdiction. You should seek the advice of a local legal professional to clarify the legality of your usage of HackRF One, Portapack and Mayhem for your jurisdiction.

Background

HackRF One

The HackRF One was originally conceived of and created by Security Researcher and Hardware Hacker Michael Ossmann. Previously Ossmann had created other devices primarily for security research in the area of RF. These devices include the YARD Stick One, a general purpose Software Designed Transceiver capable of transmitting and receiving signals below 1GHz, and the UberTooth One a device made specifically for Bluetooth Penetration Testing and Security Research.

The HackRF One can be seen as a logical progression from these devices, extending both functionality and frequency coverage.

Portapack

The Portapack was originally designed and created by Security Researcher and Hardware Hacker Jared Boone as a way to provide portable operating capabilities for the HackRF One.

Open Source Hardware and Software

All of the original source code, documentation and design files for HackRF One are copyright Michael Ossmann and licensed under the GNU GPL 2.0.

All of the original source code, documentation and design files for Portapack H1 are copyright Jared Boone and licensed under the GNU GPL 2.0.

The implications of the above are that anyone can take any of these source files and add, modify, extend and release their work, providing they make available on request, any additions, modifications and extensions they have made and license this under the GPL 2.0.

There is no restriction on using any of this for commercial gain. That being said, there is also no implication or warranty of fitness made by either the original authors or any subsequent contributors or vendors. Do your research and Caveat Emptor.

Intended Use

The HackRF One was originally designed as a tool for RF analysis and research, particularly in the domain of Information Security.

The Portapack was originally designed to facilitate the portable use of HackRF One for RF analysis and research, particularly in the domain of Information Security.

However, the HackRF One is fundamentally a general purpose Software Defined Radio. As such, it can be put to any use that a radio with similar characteristics can be. The Portapack is fundamentally a control surface for the HackRF One, and as such can be used for any general control of the SDR.

Unauthorised Access

Since much of the software and use-cases for the HackRF One and Portapack centres around Information Security Research, there is plenty of opportunity for getting into legal hot-water. The area of Security Research is as yet a legal grey-area, with many of the laws governing it being quite antiquated, and often not relevant to the technology of today. As such, it is advised that you only ever transmit where explicitly permitted, and when doing Security Research, that you only access or act upon devices you own or are explicitly permitted to access or act upon.

Transmitting

In general, it should be assumed that transmitting radio signals is not legal. Transmitting radio signals with intent, or lack of duty-of-care to cause interference, disruption or min-information even more so.

That being said, there are transmissions that are not illegal. Transmissions in the ISM bands are license-free in most jurisdictions, once certain power levels are adhered to. This is bearing the section on causing interference, above, in mind.

Amateur Radio Operators, depending on jurisdiction, license category, adherence to terms-of-license, local laws etc. have access to far more spectrum, and far higher power levels. Again, without causing interference through intent or lack of care.

Receiving

In general, in most jurisdictions, receiving radio signals is not illegal. Your specific case should be verified with a local legal professional.