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Comment by onion2k | Hacker News Reader

"Nomophobia, the fear of low battery on phones, is virtually nonexistent in China, thanks to the widespread availability of power bank stations"

Perhaps I'm more paranoid than other people, but plugging your phone in to a public USB device seems incredibly dangerous to me. At the very least someone could have tampered with it to damage the next user's device, and at the worst it could be cloning your device's entire storage.

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Well when in China you already have no expectation of privacy, so no worry there. And if you thought you could tamper and do some damage, well, remember the pervasive surveillance apparatus? Off to the dissident organ harvesting plant you go!

Aren't there USB condoms to prevent the cloning route? I don't know if that's still a thing in the days of type C.

Yes, as in cables with only the expected power/ground connectors present.

Android phones these days don't expose the data over usb unless the user chooses to.

You are best off buying a “USB condom”, a USB 2.0/3.0 connector with the data pins removed.

An actual USB condom should also include a surge suppressor.

However, the closest thing to that I have found is simple battery packs which can generally remove the need for 3rd party mid day charging.

The problem there is that the USB standard requires the initial power transfer to be low amperage, and only switches to the high amperage mode on request, with the request being delivered over the data pins.

USB condoms include a tiny chip that does the negotiation to get full power. Sometimes they even work better than the phone itself at getting the charger to give up the juice.

For up to 1 amp, three resistors is enough (that's how power banks work) -- and those easily fit inside the connector.

Cloning the storage, or any other file access, no longer works with modern devices. For example, last time I plugged my phone into rental car, I got two easily refusable prompts, to access contact list and to access files.

Damaging the device is a real deal -- I'd think more by accident than by design ("we spilled some soda on this charger... so it now gives out 20 volts instead of 5). That's why I used to carry a small USB voltmeter with me when traveling.

> public USB device seems incredibly dangerous to me.

That story is in China, where everyone is already massively monitored constantly (and this is not even hidden by their government).

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