While the risk is overblown, it exists. But it’s easy to protect yourself.
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The short answer is that it’s reasonably safe to use public USB charging stations at airports and elsewhere. While US agencies, including the FBI and Transportation Security Administration (TSA), have warned against doing so, security researchers say the threat is overblown.
“When you’re at an airport do not plug your phone directly into a USB port,” the TSA warned in a March 2025 Facebook post. “Bring your TSA-compliant power brick or battery pack and plug in there.” The Federal Communications Commission (FCC) published its own warning about these “juice-jacking” (also called “port-jacking”) attacks, but subsequently withdrew it once tech experts disputed the extent of the threat. In 2019, the Los Angeles County district attorney warned about the threat, but subsequently confirmed it had no cases on its books.
Security pros say that while the threat is real in principle because proof-of-concept demonstrations exist, there are no credible reports of any successful attacks taking place. That doesn’t mean the threat is non-existent — it’s one among a multitude of potential attacks. To keep it that way, you should always take steps to secure your device.
What is the risk of juice-jacking?
The risk of juice-jacking is inherent to the USB standard, which carries both data and power along a single cable on separate internal pins. Proof-of-concept tests have shown attackers could potentially modify public USB charging points, making them connect to the data pins in your USB cable to install malware or steal data.
One proof of concept at Black Hat USA in 2013 saw researchers from Georgia Tech present a malicious charger prototype named Mactans. They illustrated how the charger could install malware on a connected iPhone running iOS 6.
OS developers pay attention to emerging risks. For example, in the months following the Mactans revelation, Apple hardened iOS with the “Trust This Computer?” prompt you now see when you connect to a new device that wants to establish a data connection. No matter how you connect your phone, if a prompt appears asking you to “Trust” it, always tap “Don’t Trust” unless you intend to share data with that device.
What you can do to prevent juice-jacking
If you want zero risk, it’s best to not use public USB chargers at all, as the TSA indicated. Carrying a rechargeable USB battery pack, or using your own power brick and cable with a standard wall socket, are both safer options. Where available, using “Secure” charge points that block data transfer entirely can also work.
When you do have to use public USB ports, you can greatly reduce the risk with inexpensive USB data blockers, like those from JSAUX. These small dongles block data transfers but permit energy passthrough, enabling safer use of unknown USB connections. The drawback is that USB-A blockers prevent fast charging standards because chargers use the data connection to manage high voltage electrical flow. Your device will still get charged, but it will take longer. This isn’t an issue with modern USB-C blockers.
As always when traveling (and when at home), standard security advice remains the same: avoid using public Wi-Fi for sensitive information, install the latest software updates and enable multi-factor authentication (MFA) for important accounts. If you must use a public USB charging point, decline any trust prompt and consider a data blocker for added protection.
