Intro

We take our cell phones with us everywhere – which makes them the perfect tracking device. Just walking around with your device will give your location away in multiple ways. But even if you had no apps on your phone, the cellular chips in our devices will constantly be interacting with every cell tower that’s in range, negotiating the best tower to talk to, whether to use 5G or something else, and authenticating to the network – even in Airplane Mode. Cell site simulators (aka Stingrays or IMSI catchers) can be used to trick your phone into give away your location. The Electronic Frontier Foundation (EFF) has developed a cheap, easy-to-setup device that can try to discover and report these devices. Today I interview an expert panel about the clever Rayhunter project: Cooper Quintin, The Gibson, and OopsBagel.

Interview Notes

• Rayhunter announcement: https://www.eff.org/deeplinks/2025/03/meet-rayhunter-new-open-source-tool-eff-detect-cellular-spying 
• EFF’s Rayhunter project: https://efforg.github.io/rayhunter/ 
• Submitting logs to EFF: https://efforg.github.io/rayhunter/support-feedback-community.html 
• DEF CON talk on Rayhunter: https://spectra.video/w/jt9rZHCU51Rh58cBD8oiP3 
• Buy yourself an Orbic hotspot: https://www.ebay.com/sch/i.html?_nkw=orbic+rc400l 
• Gotta Catch ‘Em All: https://www.eff.org/wp/gotta-catch-em-all-understanding-how-imsi-catchers-exploit-cell-networks 
• iPhone/Android fake cell site protections: https://www.eff.org/deeplinks/2023/09/apple-and-google-are-introducing-new-ways-defeat-cell-site-simulators-it-enough 
• Meshtastic: https://meshtastic.org/docs/getting-started/ 
• Veilid: https://veilid.com/ 

Further Info

• My book: https://fdsd.me/book 
• My newsletter: https://fdsd.me/newsletter 
• Support the mission: https://fdsd.me/support 
• Give the gift of privacy and security: https://fdsd.me/coupons 

Table of Contents

• 0:00:00: Intro
• 0:02:26: Interview setup
• 0:06:18: How did you become in involved with Rayhunter?
• 0:12:08: What is a cell site simulator?
• 0:14:01: What does a CSS look like and how are they deployed?
• 0:16:55: How is a CSS used for surveillance?
• 0:20:31: Can cell site simulaters work with modern protocols like 5G?
• 0:24:09: What information can you sniff from the cellular network?
• 0:27:41: Is there any transparency around the use of CSS’s?
• 0:30:02: How did Rayhunter evolve from previous work?
• 0:35:00: How do I make a Rayhunter device?
• 0:41:45: I’ve create a Rayhunter… now what?
• 0:46:10: How can I protect myself against CSS surveillance?
• 0:49:38: Does Airplane Mode really disable your cellular radio?
• 0:52:22: How else might I defeat mass surveillance tech?
• 0:54:46: What’s next for everyone?
• 1:00:53: Interview wrap-up
• 1:03:36: Meshtastic
• 1:04:49: Patron podcast preview
• 1:05:26: Looking ahead