You might want to charge your phone before you leave home every day. It turns out that charging it in a public space could put your information at risk.

According to the Washington, D.C., Forensics Lab, when you plug your phone into a USB charging hub at an airport, shopping mall or sports arena, you could be allowing hackers to access to the data on the device.

The lab’s chief of cybersecurity, Tracy Walraven, told Washington, D.C., radio station WTOP that those convenient public ports are an easy target for hackers. Her advice: Invest in your own charger and carry it with you when you’ll be away from home for a while.

The same goes for plugging in while driving a rental car or riding in an Uber or Lyft, which Walraven calls “essentially someone else’s computer on wheels.”

Ports in some cars automatically sync with Bluetooth, which means the car could download your data—from playlists to financial records.

If “it’s a car with a hard drive or data storage mechanism in it, it’s just going to do what it’s supposed to do, which is collect data,” she told the radio station. So hackers could steal more than playlists; they could steal your identity with the information they collect from your phone.

Plugging into public Wi-Fi is risky as well, Walraven says, because anyone who is on the same network could gain access to your data. Try to avoid joining open, public Wi-Fi networks altogether.

And, to be safe, if you’re not using Bluetooth or Wi-Fi, turn the settings off on your phone—you’ll avoid being an unnecessary target for hackers and save battery life.