There's an idea for a virus:
Write a Trojan that when opened on an iPhone, cranks the volume up to 100% on all fronts.
That'd give someone a dose of medicine! Perhaps......
In any case, we don't need to hear what's blasting in your ears. Many people think earphones are a pseudo-cone of silence; they're not. Why you can't get narky at people like that for violating the "relative silence" rule on public transport is beyond me.
Then again, I haven't seen anyone get really narky about anyone flouting public transport rules; seems that people are too afraid to speak up (e.g. the culprit won't care, won't do anything, or will insult or assault them). So people get away with anything and everything: talking too loud on the phone, listening to their music too loudly (esp. if it is "undesirable" or contains "inappropriate" language), putting their feet on seats, occupying two seats when they only need one, not offering their seat for elderly, disabled, crippled or pregnant pax (even if they are in dedicated priority seats), etc....