[lxgr]

I don't care what people stare at (I'm there to stare at nature, not other people), but blasting music loudly has been a thing on some trails in the US I've been on. People don't need internet for that.

On the other hand, while this is less common (in my experience) in e.g. the alps, and people will probably reprimand you if you attempt it, I've heard some mind-boggingly loud, annoying conversations between hikers shouting across switchbacks in a large group so that everybody can hear as well. That doesn't even require a battery!

It's a social problem if anything, not a technological one. But realistically, the outdoors are pretty large – you can almost always just wait a few minutes and let people that bother you pass by.