[8note]

You are infringing if they can hear it.

That cases are not pursed is incidental.

I imagine it's hard to build a case against the guy blasting his car radio without a recording, and the affected people aren't particularly unhappy with it.

If copyright was more like trademarks, and they had to protect it to keep it, you'd see more cases of people playing their music too loud.

We'll see the same happen with streaming services as smart TVs get popular. You'll have to pay per viewer as licenses change

[jariel]

You are not infringing on anything by playing music to yourself, and it's not a matter of cases being failed to pursued, it's straight up legal to do so in every sense.

If there is some random person filming you - then they are infringing - not you.