This article by David McAlpine, Bill Thompson, and Megan Gilliver on ABC News makes the case for digital etiquette:

You step onto a crowded train and grab a spare seat to relax for your journey home, only to be met with Radiohead’s Kid A album reverberating out of someone else’s headphones, while the person behind you argues with their partner about who is making dinner tonight … where’s the digital etiquette?

I’d say it’s simpler, it’s just not being a dick, full stop.

I’m willing to give people the benefit of the doubt most times, but obliviousness and arrogance are no excuses in a public space.

When you start having fantasies about carrying around a portable, targeted EMP laser pointer thingy to discretely disable demonic devices deployed by dickheads, you know there’s a problem.