Charging on the go: why that free USB port at the station isn't always a good idea

At airports, on trains, and in hotels, free USB ports are everywhere. Convenient, sure — but not always wise. Here's how to charge safely on the go.

You're at Schiphol, on the train to a client, or in a hotel lobby. Your phone is at 12% and you've got a video call coming up. Lucky you: there's a USB port built into the armrest or the table. Just plug in and you're sorted. Right?

Not quite. Those free USB ports are handy, but they're not always as harmless as they look. No need to panic — seriously — but it's worth knowing what's going on and what you can do instead. This post breaks it down, calmly.

Why a USB port is different from a regular power socket

A regular power socket delivers electricity and nothing else. A USB port delivers electricity — and can also transfer data. Your phone can charge and exchange files with a computer over the same cable. That's normally useful, like when you're copying photos to your laptop, but with an unknown port you have no idea who or what is on the other end.

In the worst case, there's no "dumb" charger behind a public USB port — instead, there's a device that tries to read your data, install malware, or pair with your phone as a data source. This is known as juice jacking. In the Netherlands it's rare, but it's not fiction: the FBI and other agencies have been warning about it for years, especially when travelling.

When is it actually risky?

For most SMB owners, the odds are low — but the consequences can be significant. Think about situations where you're using a work phone with access to email, customer data, or your accounts. The risks are higher when:

• You're using a built-in USB port in a table or armrest (rather than your own plug in a power socket).
• Your phone or laptop is running older software.
• You see a pop-up when you plug in asking "Trust this device?" — and you tap yes without thinking.

The risks are low when you plug your own adapter into a regular power socket. Electricity from a wall socket cannot carry data.

Five simple habits for when you're on the road

1. Bring your own plug

The easiest solution is also the best: toss a small USB adapter in your bag. Plug it into a regular power socket and charge your phone using your own cable. That way you never have to use an unknown USB port. At airports and on newer trains, standard power sockets are usually available right next to the USB ports.

2. Use a power bank

A 10,000 mAh power bank costs a few dozen euros and gives you two to three full charges. Perfect for a day out. Charge it at home or at the office, and you'll never need to plug into a stranger's port again.

3. Buy a "data blocker" or charge-only cable

Small adapters and special cables exist that pass through power only — no data. They cost a few euros and clip onto your keychain. If you do want to use a public USB port, plug one of these in between. Your phone charges as normal, but no data can travel across the connection.

4. Say "no" to the pop-up

If your phone asks "Trust this device?" or "Allow file transfers?" — tap decline or cancel. You don't need that for charging. Only tap trust when you're connected to your own laptop at home or in the office.

5. Switch your phone off while charging in unknown locations

A switched-off phone charges just fine, but no data can be exchanged. A small effort for a lot of peace of mind — especially if you're going to be plugged into a lounge USB port for an hour.

What about the office itself?

This is worth thinking about at work too. For example, put a few standard USB adapters near the meeting room table so guests can plug their own cable into a power socket rather than into your laptop or docking station. It's more convenient and it prevents a guest from accidentally connecting an infected phone to a workstation.

The same goes for USB cables or power banks you find in the street or on a train — leave them where they are, just as you would with a found USB stick. You never know what's inside.

Quick summary

• A USB port can do more than just deliver power.
• A regular power socket with your own adapter is almost always safer.
• A power bank or data blocker is an inexpensive solution.
• Decline pop-ups asking you to trust a device when plugging in.

None of this means you should be worried. These are small habits you learn once — and then never have to think about again.

Want to make sure your business phones and laptops are properly protected in other ways too — with two-factor authentication, a solid password policy, and no forgotten old accounts? Take a look at our help with implementing 2FA or have an access check carried out. A little maintenance goes a long way.