I have never used someone else's charging cable and always have one on me so I can charge if needed. My reasons for this USED to be that I didn't want to tie up someone else's cable in case they needed it, I didn't want to accidentally end up with their cable and then have to go out of my way to return it or ship it to them, and lastly there are a lot of gross people in this world that I wouldn't want to have any kind of connection to, even using one of their cords to plug into something that ends up beside my face.
The new reason you just gave me is more compelling than all of my former reasons combined.
It's worse than you can imagine. These "bad" cables are so advanced now they look like proper stock cables you would buy from a company directly (like apple). You can only tell if they have been fucked with if you know what to look for, cut them up or have a x-ray machine.
I am really, REALLY, thinking about buying a xray machine.
Shit, now you have me wondering if some cable makers ship their cables wirh spying hardware and ate just harvesting our phone data when it is plugged in.
Some of the cables have wifi/bluetooth/etc radios in the plug space itself now. That's how small that tech is now. They can create a network when plugged in and depending on how your device is setup (or if there is some sort of zero-day) it can pop the device and steal anything it can find.
The world is full of terrors that most have never even tried to consider. This is stuff you can build/buy. Not even "government level" stuff.
As if I didn't make you paranoid already, here is another post. This is at least a year old. https://counterespionage.com/malicious-usb-cables/ Archive: https://archive.is/wip/t7uFo