I see a few cyclists doing that these days on the bike trails. Some of these absurd $10K+ bicycles even have speakers built into them. I guess it’s slightly less obnoxious since a bicycle will pass a walker or runner very quickly, but it’s still dickhead behavior. Even worse than music, though, is people who blast fucking preachers.
Blasting preachers is a special sort of asshole behavior I never encountered or considered before. I bet they think they are saving souls.