Why Every Bitcoiner Needs a Faraday Bag: The SLNT Advantage

In March 2025, T-Mobile was ordered to pay $33 million after attackers used a SIM swap to steal $38 million in cryptocurrency from a single customer. The attack worked exactly as thousands of others have: criminals took control of the victim's phone number, intercepted SMS codes, and systematically emptied crypto accounts.

This isn't a rare occurrence. UK data shows SIM-swap incidents surged 1,055% in 2024 alone—from 289 cases to nearly 3,000. For Bitcoiners, these numbers represent an existential threat to financial sovereignty.

Your smartphone has become the master key to your crypto holdings, whether you realize it or not. It's the gateway to exchange accounts, email resets, and multi-factor authentication. When that device is compromised—or even when it's just quietly broadcasting data you didn't know about—your Bitcoin security crumbles.

This is where Faraday bags enter the conversation, and why SLNT's military-grade solutions have found an enthusiastic audience in the Bitcoin community.

The Problem: Your Phone Is Always Talking

Here's something most people don't realize: your smartphone can continue transmitting limited data even when powered down. Airplane mode helps, but it's software-controlled and can be overridden by malicious apps or system processes.

Modern phones are constantly broadcasting to cell towers, Wi-Fi access points, Bluetooth beacons, and GPS satellites. This creates multiple attack vectors:

• Location tracking that reveals your patterns and potentially valuable storage locations
• Remote access attempts through compromised apps or zero-day exploits
• Signal relay attacks that can intercept or manipulate communications
• Passive data collection by third parties you never consented to

For Bitcoiners managing significant holdings, this constant connectivity represents a fundamental conflict with the principles of self-sovereignty and minimal trust.

What Makes SLNT Different

Faraday bags create an electromagnetic shield using layered conductive materials. When properly sealed, they block all wireless signals—cellular, Wi-Fi, Bluetooth, GPS, RFID, and NFC. Think of it as a hardware-enforced airplane mode that no software can override.

SLNT (pronounced "silent") has built a reputation as the premium option in this space. Their Multishield material meets military standard MIL-STD-188-125-2 and delivers up to 100 dB of signal attenuation—that's a 100,000:1 reduction in signal strength across frequencies from 1-40 GHz.

This isn't marketing fluff. SLNT products are used by the US military and government agencies precisely because hardware-level signal isolation is the only way to guarantee a device isn't communicating.

The Bitcoin connection became explicit in September 2025 when Bitcoin Brabant became SLNT's first official EU reseller, marketing directly to the crypto community. Their pitch is simple: if you're serious about self-custody, you need tools that match that commitment.

Real-World Bitcoin Use Cases

Hardware Wallet Protection: Store signing devices in Faraday bags when not in use. This prevents any possibility of remote tampering or data leaks from the device itself.

Operational Security: Use a Faraday bag during sensitive operations like setting up multisig wallets, creating seed phrases, or executing large transactions. Complete radio silence ensures no data leaks during critical moments.

Travel Security: When crossing borders or staying in unfamiliar locations, Faraday bags prevent device tracking and protect against hostile network environments.

Meeting Privacy: Bitcoin Magazine highlighted how users deploy SLNT bags at conferences and business meetings to ensure phones can't be used for eavesdropping or location tracking.

Emergency Preparedness: Some users keep hardware wallets and backup phones in Faraday bags as protection against EMP events or other extreme scenarios—admittedly a niche concern, but one that resonates with certain corners of the Bitcoin community.

The SIM-Swap Connection

SIM-swap attacks have become the preferred method for targeting crypto holders because they're devastatingly effective. Once criminals control your phone number, they can:

1. Intercept SMS-based two-factor authentication codes
2. Reset passwords for email accounts
3. Gain access to exchange accounts and wallets
4. Move funds through irreversible blockchain transactions

The FBI estimates that crypto-related crimes produced $9.3 billion in losses in 2024, with SIM-swapping as a key enabler. These attacks succeed because smartphones have become single points of failure for entire financial lives.

While a Faraday bag won't prevent a SIM swap that happens at the carrier level, it does provide crucial benefits:

• Limits exposure windows: Your phone can only be targeted when it's actively connected to networks
• Prevents background compromise: Malware can't phone home or receive updates when the device is shielded
• Enables controlled connectivity: You choose exactly when and where your device goes online

Beyond Phones: The Complete Setup

SLNT's product line goes well beyond simple phone bags. Bitcoin Magazine profiled their $1,000 submersible Faraday backpack—waterproof protection for laptops and multiple devices that some users see as essential for high-stakes custody setups.

The company has also integrated Faraday shielding into everyday items like wallets (for RFID protection), laptop sleeves, and backpacks. This matters because effective operational security needs to be sustainable. If your security measures are too inconvenient, you'll eventually skip them.

Legitimate Limitations and Considerations

Faraday bags aren't magic bullets. They require proper use:

• Complete sealing is essential—any gaps allow signal leakage
• Regular inspection of closure mechanisms and shielding integrity
• Understanding tradeoffs—your device is completely unreachable while bagged, including for emergency calls

They also don't address threats that don't require radio communication, like:

• Malware already installed on devices
• Physical device theft
• Social engineering attacks against services
• Compromised hardware or firmware

For some users, the inconvenience outweighs the benefits. If you're holding small amounts of Bitcoin on mainstream exchanges with standard security practices, a Faraday bag might be overkill.

The Sovereignty Angle

What makes SLNT's Bitcoin market penetration interesting is how well Faraday bags align with Bitcoin's broader philosophy. Both represent rejection of "trust but don't verify" systems.

Just as Bitcoin removes the need to trust banks and governments with monetary policy, Faraday bags remove the need to trust device manufacturers, app developers, and telecom companies with your digital privacy.

This resonates particularly strongly as Bitcoin custody scales up. River Intelligence estimates that over $1 trillion in Bitcoin is now held across various custody arrangements. As these stakes rise, individual operational security decisions carry more weight.

Making the Decision

Whether you need a Faraday bag depends on your specific threat model and holdings. Consider:

You probably need one if you:

• Hold significant Bitcoin amounts in self-custody
• Regularly use exchanges or financial apps on your phone
• Travel frequently, especially internationally
• Have been targeted by phishing or social engineering attempts
• Work in crypto professionally and are a high-value target

You might not need one if you:

• Hold only small amounts on major exchanges
• Use dedicated, air-gapped devices for all crypto operations
• Don't rely on your phone for any crypto-related activities
• Are comfortable with existing software-based privacy controls

SLNT's products start around $50 for basic phone bags and scale up to specialized gear costing hundreds or thousands. For most serious Bitcoiners, this represents a reasonable insurance premium against threats that can't be addressed through software alone.

The rise of SIM-swap attacks and the increasing sophistication of mobile threats suggest this isn't just paranoia—it's adaptation to a changing threat landscape where hardware-level isolation provides security that software promises but can't always deliver.

In a world where your phone knows everything and shares it freely, sometimes the most radical act is choosing silence.