we have collectively stopped shaming people for anti-social behavior, so these people feel perfectly fine inconveniencing everyone else around them because...no-one says/does anything.

you really only have 2 proactive choices (thay won't land you in jail)...carry around a bunch of cheap spare headphones and hand them out as a not so subtle hint that noone wants to hear these peoples shit, or carry around a water-spray bottle and spritz people like they're a dog/cat chewing something they're not supposed to.