But according to U.S. authorities, we should all think twice before plugging into the nearest charging station to revive our devices.

In a tweet on Thursday, the FBI’s Denver branch urged Americans to “avoid using free charging stations in airports, hotels, or shopping centers.”

Opting to plug your cell phone into a USB charging point in a public place could open your device up to crooks looking to tamper with your gadgets, according to intelligence officials.

“Bad actors have figured out ways to use public USB ports to introduce malware and monitoring software onto devices,” the FBI said in its tweet.

It offered an alternative suggestion for those worried about running out of power while they were on the move: “Carry your own charger and USB cord and use an electrical outlet instead.”

The advice echoes content on the FBI’s website, which extends its call for vigilance to urge Americans to be careful when using public Wi-Fi networks.

“Do not conduct any sensitive transactions, including purchases, when on a public network,” the organization advises.

“Juice jacking”

According to the U.S. Federal Communications Commission (FCC), those who use public charging stations open themselves up to becoming a victim of “juice jacking.”

This is a process in which criminals load malware onto public USB charging stations to allow them to access electronic devices while they are being charged.

“If your battery is running low, be aware that juicing up your electronic device at free USB port charging stations, such as those found near airport gates, in hotels and other travel-friendly locations, could have unfortunate consequences,” the FCC says on its website.

“Malware installed through a dirty USB port can lock a device or export personal data and passwords directly to the perpetrator. Criminals can use that information to access online accounts or sell it to other bad actors. Don’t let a free USB charge wind up draining your bank account.”

In some cases, perpetrators have left cables plugged in at public charging spots—and fraudsters may even give their targets free (but infected) USB cables as a “promotional gift,” the New York Times reported in 2019.

The FCC advises Americans to take the following steps to protect themselves from juice jacking:

• Avoid using public USB charging stations.
• Take portable chargers, car chargers, and your own USB cables with you when traveling.
• Consider carrying a charging-only cable, which prevents data being sent or received while a device is being charged.