Critical Distinction · May 2026

Your phone connects. Your IMSI ships. You never know.

Cell-site simulators near conferences, protests, federal buildings, and high-profile events. Your phone hands over its identity during the connection handshake — silently, automatically, without notification. Apple's iOS protections aren't enough. The Faraday isolation that journalists, civil-rights attorneys, and EP details rely on when the device must go silent before approaching.

Published April 30, 2026 Updated May 2, 2026 Reading time 5 min
REVIS-1 Executive Guard — Faraday-isolated phone chamber for sensitive environments
The Short Answer

An IMSI catcher (also called Stingray, after the Harris-brand variant) impersonates a cellular tower. Your phone authenticates to it, hands over its IMSI and IMEI, and the operator now has a record of every device that was within ~200 meters at that time. Airplane mode is a partial defense — software-controlled, leaves WiFi/BT on by default. Faraday isolation is the hardware defense: no signal leaves the bag, no catcher hears the device, no IMSI is captured. Phone Faraday-stored BEFORE approaching a likely catcher zone is the working protocol.

Operational Details

Numbers from FOIA filings.

75+
U.S. PDs Documented
~200 m
Catcher Capture Radius
$1.5–10K
Commercial Catcher Hardware
700 MHz – 6 GHz
Cellular Band Coverage
Trusted by Operators

Investigative journalists. Civil-rights attorneys. EP details at high-profile events. Privacy-conscious executives near federal buildings.

The same protocol used by professional EP details when the principal is moving through a known catcher-active environment — federal courthouses, embassies, conference floors, protest perimeters. Phone Faraday-stored before approaching, taken out only when communication is essential, restored immediately.

Deployment Scenarios

The three-step protocol the moment you enter the perimeter.

A federal courthouse two blocks ahead. You're meeting your client's attorney for a sealed-deposition prep. The block you're walking is well-known to the privacy-research community as a catcher-active corridor — there is documented FOIA evidence of FBI deployment, and the State Department building three blocks west has a permanent installation. Your iPhone is in your jacket pocket, registered to LTE, idle. By the time you walk into the courthouse lobby, your IMSI is in someone's logfile, alongside everyone else who walked the same block in the last six hours.
01

Faraday-store BEFORE approaching

The catcher captures during registration handshakes the moment your phone sees the rogue tower. Storing the phone in the Faraday chamber before you enter the perimeter — not after you arrive — is what works. A two-block buffer is conservative; one block is the practical minimum.

02

Take out only when essential, restore immediately

Need to make a call or check a message? Step into a known-quiet space (an elevator on the way up, a closed office), take the phone out, do the task, restore. The shorter the device's exposure window, the smaller the catcher's logfile entry.

03

For sustained sensitive activity, use a burner

Multi-hour protest, all-day conference, multi-day investigative trip — the right answer is a separate clean device used only for the activity, with the daily phone left at a trusted location. The Faraday chamber holds both: burner active for context, daily phone isolated for return-to-normal life.

Acquire

Carry quietly. Move freely.

REVIS-1 Executive Guard. Three independent Faraday-shielded chambers — laptop, tablet+phone, wallet+keys+RFID. The tablet+phone chamber sized for iPhone Pro Max plus a tablet, with 76–85 dB attenuation across the cellular bands (700 MHz – 6 GHz). The bag the journalist, the attorney, and the EP detail carry through the same corridor — and the bag the catcher's logfile never sees.

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REVIS-1 Executive Guard — Faraday-isolated chambers for cellular silence
FAQ

Common questions on IMSI-catcher defense.

What is an IMSI catcher (Stingray) and what does it actually capture?
A cell-site simulator that masquerades as a legitimate cellular tower. Your phone connects to it (cellular protocols force the phone to attach to the strongest signal in range), the device hands over its IMSI (International Mobile Subscriber Identity) and IMEI (International Mobile Equipment Identity) during the registration handshake, and the catcher logs them. Some classes additionally intercept SMS, voice, and metadata. The catcher operator now has a list of every phone that was within roughly 200 meters at that time, with timestamps.
Where are IMSI catchers actually deployed?
Documented domestic-U.S. use: federal investigations (FBI, DEA, ICE — disclosed via FOIA), local law enforcement (over 75 U.S. police departments per ACLU mapping), and increasingly at protests and political events. Documented international use: routinely deployed at major conferences, embassies, protests, and high-profile events by foreign intelligence services. Documented criminal use: organized fraud groups operating at financial-district choke points to harvest banking-app credentials. The technology is no longer a state-actor exclusive — commercial IMSI-catcher hardware costs $1,500-$10,000.
Will airplane mode protect me?
Mostly — but with two caveats. (1) Airplane mode disables cellular radios but on most modern phones leaves WiFi and Bluetooth on by default, so your device still emits identifiers. (2) Airplane mode is software-controlled — a compromised device may continue to emit cellular signals despite the toggle showing 'on.' Faraday isolation is the hardware control: no radio reaches outside the bag regardless of what the device thinks it's doing. For high-stakes contexts, Faraday is the only verifiable answer.
Can my iPhone detect an IMSI catcher?
Not natively. iOS has limited heuristic indicators (sudden network downgrade from 5G/LTE to 2G/3G is suspicious; a few apps like Cellebrite-class detection tools attempt this) but no reliable IMSI-catcher detection in stock iOS. Android has a few open-source tools (SnoopSnitch, AIMSICD) that work on rooted devices and specific chipsets — not most phones. The defense is not detection — the defense is being not-emitting when you are in a context where catchers are likely deployed.
What's the right Faraday protocol for protest, conference, or sensitive-meeting attendance?
Faraday-store the phone before approaching the venue — not after arriving. The catcher captures during registration handshakes, which happen the moment your phone sees the rogue tower; if you walk into range with the phone live, you're already logged. Take the phone out only when you genuinely need to use it, and Faraday-store again the moment you're done. For sustained sensitive activity (multi-hour protest, all-day conference), consider leaving the phone at a trusted location entirely and operating with a burner. See our hotel-WiFi protocol for adjacent travel scenarios.
Which Faraday solution is built for journalists and EP details working in catcher-active environments?
The REVIS-1 Executive Guard. Three independent Faraday-shielded chambers — laptop, tablet+phone, wallet+keys+RFID. The tablet+phone chamber sized for iPhone Pro Max, Pixel Pro, or comparable plus a tablet, with 76–85 dB attenuation across the cellular bands (700 MHz – 6 GHz). Boardroom-grade exterior so the bag works for daily executive carry AND for the day the protocol matters. Hand-assembled in the United States. $129.
Block Every Signal

Carry everything.

The bag the journalist carries through the corridor. The bag the attorney carries to the federal building. The bag the EP detail carries through the protest perimeter. Hand-assembled in the United States. Reaches your door in 3–5 business days.

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General information about IMSI-catcher defense as of May 2026. For high-risk operational contexts (investigative journalism on national-security topics, civil-rights litigation against state actors, dissident or activist work in hostile jurisdictions), consult dedicated digital-security trainers (Freedom of the Press Foundation, EFF, Access Now) for full operational planning.