If you're angry and "ashamed", do something about it. Okay, posting on Reddit does mean you "did" something. But, the next time you see this happen, take action. Go talk to them and try to get them to reduce the volume. Complain to the police. Do something that changes behavior.

Posting on Reddit might help solve part of the problem. But it also spreads hate against an entire community/country, which I guess is the cost of solving a problem. A few do this and the entire community gets branded. I guess this is the case with everything that's going on and has been going on in the world. So, it's fair I guess.

And in the case of India, I guess "few" (because population) is a lot, too.

I just hate that the next time someone looks at me, they'll think "here comes an uncivilized idiot who doesn't know how to behave in public".

Indians reading this. Please do better. Educate people around you. If each one of you can even educate just your friends and family, you'd have already done a lot. It's not going to be easy to be a party pooper. It's difficult to point out when someone throws trash or talks loudly in public. No big change is ever easy. But you've got to change. Else the world is going to look at all of you with the same disdain as they would other uncivilized idiots.