> when using an untrusted USB power source... Don't do that. Ever. Always use your own charger and cable, preferably the ones that came with the phone. If not

> when using an untrusted USB power source... Don't do that. Ever. Always use your own charger and cable, preferably the ones that came with the phone. If not make sure you're sourcing them from a reputable company and not an anonymous Chinese importer.