What is juice jacking — and how worried should you be?

Juice jacking is the use of a public USB charging port, station, or cable to reach a device's data lines — not just its power lines — in order to copy information off the device or push malware onto it while it charges. The term exists because USB was designed to carry power and data over the same connector: every time you plug in to charge, you are also plugging into a potential data connection.

What U.S. agencies actually said

In April 2023 the FBI's Denver field office advised the public to “avoid using free charging stations in airports, hotels or shopping centers” because bad actors can use public USB ports to introduce malware (CNBC coverage, CBS News). The FCC maintains a standing consumer guide on juice jacking that recommends carrying your own charger and — notably — “a charging-only cable from a trusted supplier” (FCC consumer guide).

The honest part: how common is it?

Documented, confirmed cases of criminals juice-jacking travelers in the wild are rare. When pressed after the 2023 advisory, the FBI said the warning was precautionary and not prompted by a specific incident (Slate's analysis). We make a product in this category and we'd rather tell you that plainly than sell you fear.

So why does anyone bother protecting against it?

• The attack is demonstrated, not theoretical. Security researchers have shown working juice-jacking rigs since 2011 — the mechanism is simply how USB works.
• The exposure is asymmetric. One compromised device can mean drained accounts for an individual — or, for an organization, an incident measured in millions. IBM put the global average cost of a data breach at $4.45 million in 2023 (IBM Cost of a Data Breach).
• Detection is nearly impossible for a user. A tampered port or cable looks identical to a clean one. You can't inspect your way to safety.

How the attack works, in one paragraph

A standard USB connection carries power on some wires and data on others. When you plug into a port you don't control, the equipment behind that port decides what to attempt over the data wires: it can present itself as a computer and request access, exploit a device vulnerability, or in the crudest version simply prompt you to “trust this computer” and hope you tap yes. Modern phones have gotten better at asking permission — but the defense still depends on software behaving correctly and users answering prompts correctly, every single time.

Protection, ranked by strength

1. Use your own charger in a wall outlet. No USB data path exists at all. This is the FBI's first recommendation — when an outlet is available and you remembered the charger.
2. Cut the data lines in the cable. A data blocker, charge-only cable, or switchable cable makes the data path physically absent, so it doesn't matter what the port tries. A switchable cable (this is what Lion Cables are) does this without giving up data function when you actually want it — flip the switch, and an illuminated indicator shows which mode you're in.
3. Answer the prompt correctly. If your phone asks, always choose “charge only” / don't trust. Real protection, but it depends on the prompt appearing and on you never tapping wrong while distracted at a gate.

Frequently asked questions