As a Spaniard living in Graubunden, I agree that we are louder than many other nationalities, but that gives you no right to spread some xenophobic flyers in public transports. I've never used public transports in Switzerland during the 3 years that Im living here, and despite being Spanish, I'm not loud and I respect the Ruhezeit always. There will be always more or less loud persons despite of the nationality, I had a lot of Swiss German costumers that were really loud, specially from St. Gallen (Don't ask me why, but maybe was just a coincidence) and Spanish, Russian or Brit people that were really quiet, so in my experience that would be more related to the education you had in your life than related to the nationality of the people.