If you’re in an airport or cafe, you might be tempted to plug your device into an open USB port to charge it. This can be risky, since you don’t know if the port is compromised. Charge via a wall outlet or bring your own battery pack instead.

One of the side stories of a 2018 international summit in Singapore was the provision of USB-powered fans to members of the media. Such peripherals can be dangerous. They might carry malware that can hijack connected devices. Never plug in a peripheral that you don’t trust or that comes from an unknown vendor.